Wren is an open source modular soft synth for Windows

Elk vogeltje zingt zoals het gebekt is

current version 2017.4.22.0

Quick links

The ZIP of the current version Everything executable in one zip file — you'd normally want to download just this file.
The last sources All source stuff in one zip file (2017.4.22.0 build 147).

individual links

The PortAudio DLL optional — for lower latency audio. Copy this DLL to the wren.exe folder.
The FFTW DLL optional — for FFT based modules, copy this DLL to the wren.exe folder. Par example … The vocoder module needs this DLL to be present.
The NetMIDI zip optional — for MIDI support, can be copied and unzipped anywhere you like.
The words.lpc file optional — For speech only, the talkie module can not work without this file, this file needs to be in the Wren executable folder for it to be found.
The wren.scale file optional — For SeqRandom, when not present Wren will generate a default file. This file defines the user scales used by the program, it goes into the Wren executable folder.
The looks file optional — load this into a looks sub folder of the Wren executable folder for some better looks. This needs Wren version 2015-11-04 or later for it to actually work.
The wren.formants file optional — save this into the Wren executable folder for the Formant2 module to work properly. This needs Wren version 2015-3-5 or later.
The Wren module docs Wren itself will generate these as well when a new version runs for the first time.
Some example patches Just a random collection of patches, some may be nice others less so, they all do not depend on external files other than the standard dependencies mentioned above.
The Wren forum Please use the forum for comments and requests.
Wren RSS feed. RSS feed for the forum.

Version information

Program version 2017.4.22.0 — build 147
Source version 2017.4.22.0 — build 147
Components version 2017.4.22.0 — build 50
Port Audio DLL version 19.0 — also see source code.
Patch version 6
LPC file version 2015.1.18
Looks version 2016.8.2
Formants file version 2016.3.5
Markov file version 2016.9.9
This page


Eurasian wren, Troglodytes troglodytes

Original logo made by epwhorl
Original image by Andreas Trepte.


looks for default theme

default looks

looks for gabe theme

an alternate scheme

Frequently Asked Questions

  • Installation
There is no installation, just a couple of things to do.

Make a Wren folder somewhere on your hard disk (best to do that in a non µsoft owned folder, so best not in 'Program Files') and unzip the contents of the all-in-one zip file to there. You are now ready to run Wren from that folder.

Also I would suggest to not copy Wren into any µsoft managed folder like 'Program Files' and what have you …

The thing is … you do not own your windows computer usually, µSoft does who then rents it to you, even when you payed for the hardware.
  • It will not run …
Had a user report that the program would not run in Windows 7. Turned out his antivirus was blocking it as an unsigned program that was downloaded from the web … with a message saying 'Windows cannot access the specified device, path or file you may not have the appropriate permission'.
Please fix such issues in your AV software.

The thing is … you do not own your windows computer usually, your AV provider does who then rents it to you, even when you payed for the hardware.

Had another user report repeatedly popped up access violations. It seems that this can be caused by the PortAudio DLL (or Wren's interaction with it most likely). You can read more about this on an electro-music.com forum thread. This can be tested by temporarily renaming the portaudio.dll into something like _portaudio.dll. Not being able to find the DLL Wren will then be forced to run in legacy audio mode.

It is also possible that I made a bug. There are several bug possebillities for me to choose from already, bug wise, and from time to time I discover exciting new ones too! So at any rate, please let me know about the failures :-)
  • Stuttering audio
There are some settings you may want to review.
In the Settings Screen [F3].
  • In legacy audio mode set 'process priority level' to 'higher'.
  • In PortAudio mode set 'process priority level' to 'normal'.
In the device selector (main menu: setup/devices):
  • In legacy audio use a large buffer, like 4096 … 32768.
  • In PortAudio mode use a smaller buffer like 64 … 512.
In PortAudio mode, when using ASIO the buffer size setting is ignored, and the size recommended by the ASIO driver is being used instead. So for ASIO you will need to set the buffer size from the ASIO control panel.

It depends a bit on your processor too what mode is best to use. Legacy mode is more efficient, so better suitable for single core processors, but it gives large latency values. PortAudio uses a separate audio thread so on a multi core processor the user interface and also other programs may interfere less with audio generation, also latency can be lower then.
  • The sound quality is not very good
Try setting the sample rate higher. Out of the box Wren used to run at a sample rate of 44.1 kHz, setting it to 88.2 kHz or 96 kHz makes it sound a lot better.

As of version 2015.9.10.0 I made the default sample rate to be 88.2 kHz, but when you have an earlier install the existing INI file may still set the sample rate to a lower value. So, please check the Settings Screen [F3].

When that does not work please let me know about the issue.
  • What is the display mess (when I first start a new release)
At startup Wren checks to see if the help information is up to date. When not it will generate new help info, and for some reason in order to generate the images right the images have to be made actually visible on the screen … which looks a bit odd … but it will be only once for each new release.

When you see this on every startup it may be the case that there is no write access allowed to the folder where Wren resides. It's best to not have Wren in a windows owned folder (like 'Program Files', for instance) as such may cause disallowed write access.

I've made an option to disable automatic doc file generation. This option is off by default (so docs will be generated out of the box), and this feature will only work when you use the old wren.ini file, e.g. when you copy the new executable over the old one (or copy the old ini file to the new location). You can always manually generate documentation from the Settings Screen [F3] by using the 'generate documentation ...' button there. Note however that when no docs were generated the popups from the module selector will not show a module, or an old version of the image.
  • Troubleshooting
Try to see the Debug Screen [F5], Wren logs some information there. When you right click on it you can highlight the text, and then with another right click copy it. At times I will ask for the information present there to help troubleshoot issues. By default this information is written to a log file in the Wren application directory as well, look for wren.log.
  • Module help
All modules have some built in documentation, you can use F1 on a selected module to see it. When doing for this the first time (or after a program upgrade) the program may have to regenerate the help files, causing the some display clutter.

Right click on a module and select Help from the popup menu, this will show the same description as the generated help file.

Also when you hover over the module selector with the mouse, popups will be shown with some even more compact information along with an image of the module.

The generated help information is also used as a cache for module images to make them look a bit nicer when you hover the mouse over the buttons in the module selector.
  • Can I hear it?
I'll often have a live stream going with at least a large part of the sounds being made by Wren. This usually will be some self playing patch(es), but you may catch me in live bug finding too, YMMV …
  • Where is my patch
Hit F2 to return to the patch editor.
  • Where does that wire go
Click and hold on a connector, the whole connected wire net will be highlighted.
  • I can not read the display values, it's all covered by wires
Use Ctrl+space bar to wiggle the wires, the value might become readable then. Otherwise hover the mouse over the knob controlling the display. Not all controls have a value showing popup yet, but working on that. Alternatively, set the wire size to zero to hide all wires (this is the up/down control in the top pane, labeled with 'wires'). It is also possible to temporarily hide the wires using Ctrl+W, press Ctrl+W again to make them visible again.
  • The wires are not visible in the editor
The wire thickness may have been set to zero, in the editor top pane under 'wires' you can change this with the up/down control. It may also be that the wires were set to be invisible, use Ctrl+W to toggle wire visibility. For me running Wren under Wine on OSX 10.10.3 (Yosemite) showed some issues with wire painting, I have no cure for that.
  • There is a reverb in my patch, but where is it?
Use Ctrl+F to find modules in the patch by name, partial matches will be highlighted as well. For instance, search for 'verb' to find all modules having that bit of text in their title. Found modules will light up their title bar. This feature can be enabled from the Settings Screen [F3]. Clear the search box by pressing the Esc key.
  • There should be a module with a name like verb, but on what selector page is it?
Use Ctrl+F to find modules in the module selector by name. All modules not found will be hidden, and all pages that become empty this way will be hidden as well. To show all modules again clear the search box. This feature can be enabled from the Settings Screen [F3]. Clear the search box by pressing the Esc key.
  • Polyphony
Wren is a monophonic synth. Still you can of course have multiple sounds or even multiple synths by patching them out. The MIDI interface will need to work on a different channel though for each voice added this way, as it can handle only one note at a time. I've added a four channel MIDI input module to allow for manual patching of a fourfold poly synth.
  • Inputs and outputs
Inputs are round, outputs are square. The color indicates the signal type where red is an audio rate signal and blue is a control rate signal. Yellow indicates a logic level signal, usually -1 or +1 but there are exceptions where the values are 0 or 1. Lime (bright green) indicates a control rate logic signal. You can freely mix all signal types, the color is just a hint, although a Blue or Lime input will not see all samples of a Red or Yellow type signal (often this will not matter). Some modules are rate smart, they will adjust their calculation rate from control rate to audio rate when an audio rate signal gets connected to one of it's inputs.
  • How to add wires
Click and hold on a connector and then drag to another connector, then release the mouse button. You can connect inputs to inputs and inputs to an output. It is not possible to connect an input to multiple outputs, and it is not possible to connect an output to an output. It is not necessary to connect each input to an output separately, you can make a chain connection from input to input … to output. When a connection chain is not connected to an output it will have a highlight color to indicate this, otherwise it will have the color of the output it is connected to (the color can be changed from the connector popup menu).
  • How to (re)move wires
By using Ctrl+normal mouse click, drag the cable to another connector to reconnect it, or into the void (anywhere but on another connector) to make it go away. There also is a connector context menu (accessible with a right moue click) with some options for wire removal.
  • How to change parameters
  • Knobs — it depends on the mode you have set in the Settings Screen [F3]
    • circular — a mouse drag around he knob changes it.
    • horizontal — a horizontal mouse drag changes it.
    • vertical — a vertical mouse drag changes it.
    Additionally when a knob is active, that is when it's up/down clickers are visible (and it has a red (or fuchsia) border too then), you can click on the up or down clicker, or use the cursor up / down keys. A knob can be made active by positioning the mouse cursor over it or by tabbing to it.
    You can also enable the mouse wheel on knobs in the Settings Screen [F3].
    There is another knob variant that has no knob but only the up / down clickers, this type will listen to the arrow keys when selected (and to the mouse wheel as well, when that was enabled).
  • Sliders — these can be either horizontal or vertical and will behave as if they were knobs, but the mouse drag mode is restricted to horizontal or vertical only. They will respond to the mouse wheel too, when the mouse wheel option was enabled.
  • Selectors — these look like displays, but have a yellow border. You can click on a selector to get to the next value, or right click on them to get a popup menu to select a value from. Selectors also can get focus by positioning the mouse over them, when they have focus the the up/down arrow keys can be used as well to change the values.

    Some selectors act as momentary switches, or buttons, these will have a white border.
When wheel mode is used just hover over the knob and wheel the wheel. Moving the mouse over a knob will set it to be focused, and once a knob is focused the keyboard up/down arrows can be used to change it's values too. A knob can also be selected by tabbing to it. There are also vertical (and horizontal) sliders those will only support the vertical (horiontal) move mode (along with the mouse wheel mode, when enabled). Selectors will also receive focus when the mouse is moved over them.
  • right mouse clicks
  • On a knob — set default value or lock / unlock the knob (a locked knob will not listen to mouse control changes).
  • On a connector — break a connection – there are some options to select from.
  • On a module — Cut copy or delete it, or change its border color etc.
  • On a selector — selectors have a yellow or a white border, you can right click to get a popup menu for selecting a value.
  • On a graph — some preset curves can be selected, a couple of symmetry options are available and the graph can be saved to or loaded from a file.
  • On the editor background — module options, like copy paste, module insertion.
  • Change module caption
Double click on the module caption, an editor pops up then. When done hit Enter to commit the changes or Esc to discard them. A changed module caption when moved over by the mouse will still show the module's type. When the first character of the module title is '@' the module is enabled for receiving OSC messages.
  • How to edit module titles or text based controls
Double click on it, or tab to it and use the Enter key. And to close the editor use Ctrl+Enter. Module titles and single line editors just use Enter.
  • How to close a text editor
Use Ctrl+Enter to save the changes, or Esc to discard them. You can also click outside the editor to make it go away (and discard changes). Single line editors can be closed with just Enter as well.
  • NetMIDI setup
Run NetMIDI and Add a server there. In the newly created server tab fill out a couple of details :
  • You can type a name for the connection (this is not a formal thing, just a reminder for yourself).
  • Type a TCP/IP port number, Wren by default uses port 31415, but you can select something else if you wish. This is pretty arbitrary, except that the port number should not be in use by any other running programs — you'll get a conflict message later on when you try to do that.
  • Select some physical MIDI ports from the drop down lists on the right. You need not select both an input and output port when you do not need both.
  • Tick both checkboxes 'Auto start on load' and 'Disable Nagle'.
  • Start the server, Windows may now popup a dialog asking you to allow NetMIDI to open a server port, say yes to that.
  • Window may complain that the port is in use already, in that case you'll need to provide some other port number.
  • You can check if the MIDI ports work by looking at the lights.
Next you'll want to setup a NetMIDI connection for Wren, you can do that from the Settings Screen [F3]. Under 'netmidi / midi tangle settings' do the following :
  • When NetMIDI runs on the same computer as Wren enter localhost as the server (or When the programs do not run on the same computer you will need to enter the computer name of the remote computer where NetMIDI runs — or it's IP address.
  • Enter the port number that you filled in for NetMIDI.
  • Click Apply.
  • Click Connect. A client entry should appear in NetMIDI in the unlabeled box left of the lights there. Also in Wren the small 'c' light should light up (in both the Settings Screen [F3] and the metering panel).
  • The two extra lights in Wren 'r' and 't' indicate reception and transmission respectively.
  • When you check 'auto connect' in Wren it will try to establish a NetMIDI connection automatically after startup, and it will connect as soon as NetMIDI runs.
  • OSC setup
Each Wren instance can either be an OSC transmitter (client) or an OSC receiver (server), but not both at the same time. The client / server indications are the official OSC terms as used here.

There can be multiple listeners (servers) on one computer, but you can have one transmitter (client) only on any single computer (but you could have more transmitters (clients) spread over multiple computers).

When everything is set up correctly the Wren instance should be able to talk to or listen to any OSC enabled device (or software) present on your network (or computer). It is not possible to broadcast OSC messages out of your local network. With the proper holes set in routers etc. it should still be possible to set up a single transmitter (client) to receiver (server) link though.

To set up Wren as an OSC transmitter (client) do the following:
  • In the Settings Screen [F3] look for the OSC settings box.
  • The IP address must be set to a broadcasting address to allow for multiple receivers, otherwise the IP address of the single receiver can be used. The address to use depends on your network configuration but selecting should always work. Locally I use as the address which will reach all computers in the address range 192.168.1.x. When everything is on one computer using or localhost may work too.
  • The port must be set to a number not in use for any of the participating computers. When you select a port that is in use you will not be able to transmit a test message later on, and OSC errors will be reported in the log (OSC error logging is on by default, OSC message logging is off by default).
  • Check the Use OSC checkbox.
  • Click the Apply button
  • Send test messages using the button, the 't' light should light up on each transmission. When it does not light up you probably selected a port that was already in use, so try another one.
To set up Wren as an OSC receiver (server) do the following:
  • In the Settings Screen [F3] look for the OSC settings box.
  • The IP address must be set empty (internally will be used in that case, but the field being empty will open the UDP socket as a listening (server) socket, filling in anything will open it as a client socket).
  • The port must be set to the same value that was used to set up the transmitter.
  • Check the Use OSC checkbox.
  • Click the Apply button
  • Send test messages from the transmitter, the 't' light on the transmitter and the 'r' light on the receiver should both light up on each button click. When they do not light up you probably selected a port that was already in use, so try another one. The test button is only available on the transmitting side.
The test button sends a single OSC message to the address /*/testmessage with a float value of 1.000 an integer value of 1001, and a string value of '1002'.

There is no OSC connect light as OSC is used over UDP, a connectionless protocol, so there is no concept of connection but only of transmitted and received packages of data. There is a light indicating OSC to be active though, the 'a' light (in the I/O control section on the right side of the screen).

The OSC listener (server) implementation used does not send replies to to the transmitter (client).

The lower level protocol used to transmit the OSC messages is UDP. UDP messages are not guaranteed to be received in the same order as they were sent, or in fact not guaranteed to be received or sent at all. Usually it will work, but on a busy network packets may get lost. Also it is possible to send OSC messages faster than the network can get them out, in that case not all messages will be sent.
  • What OSC functionality was implemented
OSC time stamps are not supported, bundled messages can be received but are not processed currently. Bundles are not transmitted currently. All message handling is immediate.

Note that each address can be used only once in a patch, when it occurs multiple times an arbitrary OSC handler will handle it and the other handlers will think it to be handled after that. You can have multiple transmitters using the same address though.

The following addresses are currently being used:
  • /*/testmessage can be sent (from an OSC transmitter only), this is a single OSC message with a float value of 1.000 an integer value of 1001, and a string value of '1002'.
  • /<synthname>/sync can be sent and received by the Sync module. This message has no parameters. The message is received when the current Wren instance is set to be an OSC receiver. the message is transmitted when the current Wren instance is set to be an OSC transmitter. Sync messages are naive, they assume zero time delay between transmitter and receiver.
  • /<synthname>/<user_defined> for the OscMessage module, this will send or receive a single float message. Messages with a matching address with more than one parameter can still be processed as long as the first one is of type 'f' (float). To force a value to be sent out the trigger input needs a low to high transition – you could put an LFO on that, or make a change detector based upon a sample and hold, or use the differentiator module.
  • All modules can receive OSC messages when the module title is set to start with an '@' character. They then can be addressed with a /<synthname>/<modulename_without_@>/<control_name> pattern. The first value in the message must be of type 'f' (float) with a value from zero to one, with zero mapping to the lowest possible knob value and one mapping to it's highest possible value.
  • How to get Wren to play with JACK
What I did:
  • Installed JACK, I've used the mixed 64/32 bit version.
  • Followed the 'Installation and Configuration' section from http://jackaudio.org/faq/jack_on_windows.html
  • Set JACK to run at the same sample rate as that I run Wren on, this seems to be needed or Wren will not open the JackRouter connections (so sample rate conversions seem not to be possible).
  • Started Wren, and then from Setup/Devices (in Wren) selected the ASIO API, and then for both the Input and Output devices I selected JackRouter. Note that this means means that you'll have to use the Port Audio interface.
  • Then for the 'In channels' I selected all four that were present and for the 'Out channels' likewise. The number of channels is configurable for JACK, four being the default. Wren only supports 8 channels, but these should be selectable arbitrarily from the JACK set.
With this I was able to get audio out of Wren into JACK and out of JACK into Wren .. and it looks like I get an exact copy of what I send in channels 1 and 2 back in the inputs 1 and 2.

NOTE: Wren has no native JACK support … of course … I'll look into that, but it will be a long term project – the C header files will need to be ported to Delphi.

NOTE: To see some error reporting in Wren you can try the Debug Screen [F5], it may show a reason for not being able to connect to JACK.

NOTE: This will allow for audio integration with your DAW, assuming that the DAW uses ASIO.
  • Using module colors
In the Settings Screen [F3] you can set a default color and an opacity value. The opacity value determines the saturation of the module colors. In the patch editor you can select the modules to be colored, then right click on any of the selected modules and select the color option from the popup menu.
It is also possible to use the module standard colors, both for new modules added and from the module popup menu.
Module colors will be saved with the patch.
  • Using wire colors
Wire colors can be changed by right clicking on a connector and then selecting one of the color options from the popup menu.
Wire colors will be saved with the patch.
  • What are the modifiers which can be used on values.
NOTE: this does not work properly.

(blank) nothing
mHz (milli Hertz) aValue = FrequencyToUnits( aValue / 1000)
Hz aValue = FrequencyToUnits( aValue)
kHz aValue = FrequencyToUnits( 1000 * aValue)
bpm aValue = FrequencyToUnits( aValue / 60.0)
degrees or deg aValue = aValue / 360
radians or rad aValue = aValue / ( PI * 2)
percent or % aValue = aValue / 100
ms aValue = aValue / 1000
s nothing
nn aValue = NoteNumberToUnits( aValue)
qsteps or q aValue = aValue / 1000
ct (cents) aValue = aValue / 256
other modifiers will fail

Also in a context where unit modifiers can be used note names may be used, e.g. A0, A0# etc. but note that only sharps can be used, there is no notation for flats. The general notation is N[#][-]n where the bracketed items indicate options, N is a base name and can be AG, # indicates a sharp and [-]n is a numerical octave shift. Note name A4 maps to note number 69 which in turn maps to 440 Hz. The mapping to 440 Hz can be changed in the program options. [Note: Note names do not work yet (except in sequencers — where the feature can not be turned off yet), a couple of headache things there still.]
  • What internal scaling is being used
The mHz, Hz and kHz modifiers use a scaling of 1/128 units per semitone, units can be negative values for low frequencies. The nn modifier uses a scaling of 1 per semitone, note numbers can be negative or fractional just like frequencies can be. By default note number 69 (A4) maps to 0 units and there are 12 notes in an octave but this can be changed by the user. A cent is a fixed interval of 21/1200, it does not scale with the note number mapping (or actually it may, but that needs to be fixed then, please let me know where it hurts).
  • Graphs mode
To use the Graphs mode it needs to be enabled first, this can be done from the Settings Screen [F3] in the debug section. Having the graphs disabled may save some memory resources.

When graphs are enabled F4 will bring you to the graphs screen. This can be useful to help understand signals in a patch.

Graphs mode is not a real time mode, so you will need to stop audio generation [F9] or it will not work.

The graphs mode output will show output for all eight channels, so you can connect up to eight signals to be graphed simply to an output module. It can be handy to have a mixer before the output module to to trim the levels.

Before generating graphs audio must be stopped and then the 'Debug step' and 'Debug run' will draw the signals present at the output module. When audio is running the debug mode can not be accessed.
  • 'Debug reset' will clear the graph, and it will issue a patch reset.
  • To just clear the graphs use the 'Clear graphs' button.
  • While a debug session runs the reset button (F7) will work too, this will reset the patch without clearing the graphs.
As graphing gets pretty slow when a lot of points are present the graphs will be auto cleared when some arbitrary (large) number of points is in the graphs.

You can zoom in on the graphs by dragging out a view area with the right mouse button from top left to bottom right (the reversed drag direction from bottom right to top left will zoom out to full view).

Panning uses a left mouse button drag (this is slow when some data is present). Reversed right mouse button drags will cancel pans as well.

When zoomed in or panned a graphs clear will not cancel zoom or pan, you may want to do that manually to get an image again.
  • The patch randomizer / mutator, what does it do?
The randomizer is just that, it randomizes controls. This can be done for a single conrol (from it's context popup menu), for a single module (from it's context popup menu) or for a group of modules (from the module context popup menu, or from the action menu). The amount of random can be set from the randomizer / mutator window. Low values will leave the patch more as-is than high values.

The mutator implements a primitive genetics tool. The idea is that the parameters of the patch form a genome. This genome can be altered by the mutator in a sexual and in some asexual ways.

The graphic images are a visual interpretation of the parameters present in the patch. Every parameter is represented by an angle, and then a line is drawn under that angle to the next parameter – which forms the worms. Worms are then scaled to fit the cage they are in.

Asexual reproduction can be plain random … which does not really reproduce anything (as all information is lost), or a mutation (which does keep some information and looses some as well). Mutations can be controlled with a probability and a range. The probability sets the chance that a a change occurs, and the range determines how much of a change can occur.

Sexual reproduction picks parts of one genome and parts of another and makes a mix of that. The crossover probability determines how often a parameter pick switch is made from the first to the second 'parent'. Also in sexual reproduction there is some mutation involved.

In the randomizer window the parents are in the breeder bit, the leftmost one being one parent and the rightmost one the other.

The mutate button just mutates the existing worms between the left and the right parent. The randomize button sets random genomes for the same six and the mate button performs the sexual thing with both parents leading to a a sixling … erm … if that is a word.

And then you can drag around stuff, like drag a worm onto the patch worm to make the patch have the dropped params. Or drop something on the left morph and something else on the right one, and then you can do a live morph between those.

The scratch area is just that – drag stuff there for later use in one of the active squares.

Clicking on a worm will copy it to the patch, this happens for the morph and scratch things in the same way … but you can also drag worms to the patch square.

Then when you have a left and a right morph the live morph control can fade between the two. This can also be automated by using a LiveMorph module in the patch, with a checkbox to enable or disable the function, this function is disabled at program startup – to avoid possibly confusing things to happen in a patch.

… when done recursively … that is, pick a nice genome for one parent and another nice one for the other … and breed and repeat … you can do some manual eugenics on patches. And the scratch area can hold a smallish population. Oh and you can kill too of course – that's what the eraser is for – drag drop the eraser on a worm and it ceases to exist (which can be done on the scratch area only). Nice in this case meaning that you like the sound.

For both the randomizer and the mutator exclusions can be set. Some exclusions are set by the system for parameters that would make no sense to be randoized, or which would need patch recompilation when changed. Others can be user enabled or disabled, all from the context menu popup.

Excluded ccontrols and modules will get a red border in the exclusion visibility mode (this can be turned on or off from the action menu). When the randomizer / mutator window is visible (view menu) this mode will be on as well.

There are a couple of keyboard commands to – those are listed in the Action and View menus.

The forum thread is here, it may have some info not listed here.

General information


  • Wren is not a Clavia Nord Modular clone, and it will never be that. Where the user interface might suggest it to be a clone, such is the case only because I've been using Nord Modulars for a long time and the Nord's make sense to me. The modules themselves were either made by me from scratch or obtained from open source algorithms I found on the internet. They were not meant to duplicate a Nord Modular but to create modules that I wanted to be part of the system.
  • Wren is not a product, but a hobby project that got out of control a bit. This software ain't good for anything and it will crash your PC too.
    That being out of the way, for questions or remarks please use the forum I made for this. I do hang out at the electro-music chatroom too at times. I'm open for requests, but do not promise anything. I may fix bugs when it's easy to do so too!
    Contributions are welcome :-)
  • When you really deeply hate Wren you can use the source code to make your own,better, working, version :-)
  • For any legal issues it is best to use my email address to contact me, the address is in every source code file near the top, and near the bottom of this page in the License section.

Compiling your own version

  • Download the sources, NOTE: this is not always the most recent one ( I'll update sources on request though — and after every so many executable releases). This code, source and executable, is released under the GNU General Public License version 2 — see the license section.
  • You will need Delphi to compile this code (I used XE5), and :
  • You will also need the overbyte ICS package to be present in Delphi.
  • You will also need the Wave Audio package to be present in the project. This package needs not be installed, it being in the search path will do.
  • Then before Wren can be compiled my knobs2013 components must be installed (these are included in the source release as a separate zip file). I used Delphi XE5 to make this code.
    To compile the components into Delphi you need to compile the design time package and then install that one. This is the Knobs2013Design package. You'll also want the path to the components to be in your Delphi search path, or the Wren compile will fail.

Feature requests

  • ? : Abstractions … as I understood it 'patch as a module', hiding implementation details.
  • Convolution with samples.
  • Stream I/O … like shoutcast probably, but that would mean messing with mp3 coding (e.g Lame).
  • Random wave from some directory … a trigger for selection I guess, or an index input rather.
  • pre computed bandlimited PCM oscillator, see www.youredm.com/wp-content/uploads/2012/12/saw6.png
  • 2014-12-05 : Z input on scope.
  • 2014-12-13 : Soft clipping for resonator.
  • 2015-06-19 : 1D and 2D (game of life) cellular automaton sequencer.
  • 2015-06-19 : Markov chain sequencer (note: the Poetry module is based on a hidden Markov like model internally).
  • 2015-08-28 : True FM on pitch shifter. The modulation now ranges over -24 – +24 semitones.
  • 2015-09-30 : Perceptron, see http://electro-music.com/forum/viewtopic.php?p=413579 for more info on this.
  • 2016-02-04 : Gabe had an idea for an FFT based envelope generator … or more accurate envelope parameters for a handful of frequency bands .. like when you feed it noise but you'd want the highs to decay faster than the lows you could bring down the high frequency fader … something like that. It was illustrated with this image.
  • 2016-04-29 : Nord like drum module(s).
  • 2016-07-05 : VST 32/64 support … had been requested a couple of times … maybe some day I'll ddive into that … not using any plugin stuff myself currently though.
  • 2016-07-19 : Implement a randomizer function. For a set of selected modules the knobs should be set at random positions. Probably just the automatable knobs (which do not result in recompilation). This can be done on selectors and knobs easily.
  • 2016-07-27 : Celestial bodies? A time module could give like current ms, s, m, h or fraction of day, etc. Could do moon as well – there is some celestial stuff in the Chatty / Hellbo / Zombo code.
  • 2016-09-26 : Implement stuff from the Synthesis Tool Kit …
  • 2016-11-17 : Knob automation.

Known Issues

  • 2014-04-01 : Setting values from displays associated with knobs does not work. It does seem to work for oscillator frequencies and cents settings though, and for linear LFO frequencies.
    2015-09-13 : the unit system is not properly unified .. when I type 0.2 Hz for an audio oscillator it gives me a period time of 5 s alright, but entering 5 s for the value just does not work. Could easily change this, but then typing 5 s for an envelope time would not work .. will need to rethink some stuff there.
  • 2015-01-20 : Need proper error handling for syntax errors in words.lpc.
  • 2015-08-14 : Currently under Wine the popups on the knobs were reported to not go away. Actually there is more painting that is off, various screen elements are drawn too large, audio generation is not good either and it eats a lot more CPU than it should. Not that it was ever made to run under Wine of course, but would have been nice … anyways YMMV … I tried it with Wine on a Mac, maybe Linux behaves better?
  • 2016-06-01 : When 'allow undo after patch save' is enabled sometimes patch changes will not be detected after a patch save was performed – beats me …

    Actually it is worse, the changes are not seen at all, and the compiled patch will not change, leading to patch edits not having any effect at all. Or maybe F12 would still work, not tested.

    A change on a text edit may trigger this?

    But only sometimes …
  • Live morphing fucks up the undo history. This is a tough one :s
  • Could not type the character 'r' into the searchbox anymore … as it is the shortcut key for a randomize action now. Likewise for the characters '1' to '8' which select variations. Fixed that.

    Hmm .. and now some function keys do not work when the focus is on the search box.
  • When there is a lot of excluded stuff the worms tend to all get very similar, maybe the common stuff should be left out in drawing them.
  • Everything that is excluded from randomiztion will get the same value in all variations – this seems a bit overly restricted. What could be done is that variation values are initialized to the default value, and changes affect the current variation only. Still some parameters are best not varied over variations, like the delay range for a delay module. This will need some thought.
  • 2016-06-19 : DataGraph may need a point cache to speed up lookups in spline mode.

Changes ~ Fixed issues ~ Features

Currently working on

  • There is an issue with the Seq16 module in that it will sometimes not run due to the number of steps being seen as zero, I've fixed this. Meanwhile a workaround is to press F7 or F12 to make the sequencer run again.
  • Upped the maximum count values for the triggerable oscillators and LFOs. This will change existing patches using these modules.
  • Added Hold mode on EnvAHD module. When on it prevents the module from going into Release as long as the trig input is still active. When off the module works as it alwas did.
  • Added an active output to the LfoTrig modules. This differs from the inverse of the ready output in that ready will never be active before the first cycle ran (and the module will not run then yet when it saw no trigger signal).
  • Added some swell control to the EnvAHD module. Swell when active will cause a rise during the hold phase of the envelope. The amount of the effect can be preset and modulated, and the shape can be selected. The time for the swell is the current hold time. The envelope graph more or less shows the effect of this new control.

in version 2017.4.22.0

  • Moogfilter could produce denormals - added some guards there. Also optimized the filter a bit (20% off from the execution time), but it still uses an awful lot of cycles – more than a reverb does – I don't really understand why that is.
  • Compressor could produce denormals - added some guards there. Pluck module idem.
  • Graph Image for S shaped attack on the ADSR envelope module was wrong, fixed it.
  • Made the S attack and decay modes working on the Seq16 module, they acted like exp by mistake.
  • Added code for trying to get some better idea as to why PortAudio initialization failed. It will report failures to the logs.
  • Added an off-beat output to the EuclideanRhythm module, it is active whenever the regular output is not (and the clock is active). Basically it runs the reverse pattern of the regualr output.
  • Added an invert input to the Seq16 and the Sequencer modules. In invert mode the sequence is put upside down.
  • Added inputs to the Switches4 module. When these are not connected it will behave as it used to. And when they are connected they will be switched to the outputs.
  • Added range modulation to NoteQuantizer, ScaleQuantizer and ModQuantizer modules.
  • Added tanh( x) function to the Monadic module.
  • Added chain inputs to the TransInv module, these are just added to the calculated output signal.
  • Made the pulse delay module rate smart – however – the shown times are eight times as short when the module runs at audio rates (this is being indicated in the displays). Also made the MultiCompare module rate smart, so that now all the logic modules can switch to audio rate computation.
  • Added some values to the MConst module to make it usable for controlling note intervals. uni (0), mi 2nd (1), 2nd (2), mi 3rd (3), ma 3rd (4), 4th (5), dim 5th (6), 5th (7), mi 6th (8), ma 6th (9), mi 7th (10), ma 7th (11) and octave (12). These values are TET based and are fixed, even when the main tuning is changed.
  • Added a sent output to the MIDI CC output module to allow for easier sequence control.
  • Added a clear input to the Delay module, when it goes from inactive to active it sets all the delay memory to zero. This is glitchy, as it was intended to be.
  • Added input attenuation controls for the Formant and Formant2 modules.
  • Added a speed input for Osc, Square, MultiOsc, OscTrig and Squaretrig oscillators. This basically is linear thru zero frequency modulation. When speed is set to zero these oscillators will stop and they can be used as lookup tables by controlling them from the pm input. And while at it … also added speed controls for Lfo, SquareLfo, LfoTrig and SquareLfoTrig modules.
  • Changed the maximum acceptable input level for the GVerb module to 100, in the original code this was 1e5 or so and had that lowered to 10 before – but it could cause distortions that way … so upped it a bit. These are silly levels, but this can happen when the input level is high and the ouput levels are set low to compensate for that. Which would be silly to do probably, but I needed some more forgiveness there.
  • Added a 'hold' mode for the EnvAR, EnvARRetrig and EnvConrol modules, when active they will not enter the release phase as long as the trig input is still active. Also removed a possible click from these modules ( on the transition from Attack to Release or Hold mode) and removed some needless calculations … like subtracting Ln( 1).
  • Added mode selectors for the FixedDiv and PrimeDiv modules, thes can be set to either Square or Pulse. In Square mode the outputs will all have a 50% duty cycle and in pulse mode they wil be active for one positive input clock time.
  • Added a reversed mode for the arpeggiator, and added a reverse input for playing the arpeggio backwards. The reversed mode plays the notes in reversed order of reception i.e. last note first. Also added a transparant mode, when the Transparant control is active no arpeggiator actions takes place but instead the last sampled input value is being output when the output clock goes active (making the module behave like a sort of a sample and hold module (except that it has two sample clocks then).
  • Added a trans(parant) input on the Poetry module. When it is active no poetry generation takes place but instead the last sampled input value is being output when the output clock goes active (making the module behave like a sort of a sample and hold module (except that it has two sample clocks then).
  • Added count modulation inputs for LfoTrig and SquareLfoTrig modules.
  • Added a level modulation input for the Quantize module.
  • Made the control decimation programmable, it can be set from the Settings Screen [F3]. The default value is 8, what it always had been, but it can be lower or higher now. Higher values will mean that less processor resources are being used. Changing the value however also means that some modules will run faster or slower, this affects some of the blue filter modules i.e. the slew times may change etc. It is of no concern for the red (audio) filters though.
  • Seq16 - Canon outputs on seq16 Working on some MANIAC features …
    I've dded cross fade modulation to the Seq16 module and also added a random input. The random input will set all the faders to random positions. Added three 'canon' outputs, these are shifted by four steps for each one. So when the first output outputs step1 the 2nd out sends step 5, etc. This way the sequencer can be used as a 2 x 8, 3 x 6, 4 x 4, … sequencer, but it is also possible for instance to set like 12 steps and use output 1 and 3 and then they will have eight sliders overlapped and four unique ones for for themselves. The xfade works on all four outputs, but there is still just one chain input which is being added to all four outputs. Added a 'hold' input, which when active will hold the last sequencer output value and it will also block the chain outputs from being updated, but it keeps the sequencer running. Then added skip inputs for each step, when a skip input is active that step will not be used (making the sequence a step shorter). Added a clockskip input too, when it is active the sequencer will freeze at its current step. This is different from the Active input in that the Active input outputs no step values but passes on the chain outputs only. When a clock is being skipped the current step and output values will be he held and the chain inputs are no longer sampled. Then I went on and made 16 step outputs, going active when the step is active and the incoming clok is high or the trigger mode is set to (G)ate. Oh, and also added a TimeWarp (tw) output, which can be used to control the speed of the driving clock, it is meant to drive the speed input of an LFO. The idea is that when steps are being skipped the sequence length can be kept the same when using the TimeWarp output in this manner.

    Getting closer to the M.A.N.I.A.C.
  • LUT - LUT changes Added the 'canon' outputs on the LUT module as well. Added a 'steps' control as well to map a zero to one signal range on the the set number of steps, step count can also be modulated. Then added a random input for doing fader shaking too. With a negative step count (which can be set trough the steps modulation input) the unit will run 'backwards' – that is – for larger selection values it will move to a lower step value. Note that with fewer steps and a ramp on the input there will be less steps in the same time, so when used as a sequencer the sequence will run slower then. Added 16 step outputs here too, there is no clock or active input on this module, so the step outs are active for the whole time the step is active.
  • DCBlock - A DC blocker Added a DC blocking module with a -3dB point that can be set from approximately 20 ~ 40 Hz to 400 ~ 800 Hz in audio rate (red, depending on sample rate) mode and from 2.5 ~ 5 Hz to 50 ~ 100 Hz in control rate (blue, depending on sample rate) mode. The further the knob is turned right the higher the cutoff frequency will be. DC will always be totally blocked no matter what value the cutoff is set to. Feedback delay lines (and there are a couple of other modules that do not like DC very much) can lock up when there is DC present in the loop, this module can be used to get rid of the DC, probably best before the loop and not inside it.
  • MidiPCOut - A MIDI Program Change output module Added a MIDI Program Change Output module, also featuring a sent output for easy command sequencing. It will send out a a program change message when the gate goes active or when the program is manually changed. The actual program is the SUM of the values read from the prg control and the progr input. A change on the progr input will not trigger a message to be sent – a gate signal is needed then.
  • MidiPNOut - A MIDI Parameter Number output module Added a MIDI Parameter Number Output module. This module can send both RPN and NRPN data and it can do so with the most significant septet only or it can send both data septets. Added the chain output to this one as well. Data will ony be sent when the gate signal goes active.
  • Compressor - Compressor changes Changed the compressor looks a bit. The LED scale was not very informative (as the scale is pretty large things barely moved, and there was no feedback on actual gain either) so … removed it, but added a dB value indicator showing the current amplification.

    Also added a side chain input and output. Effectively this is a 3rd compression channel where the compression is being calculated on either the side chain channel (side mode) or on the stereo signal channel pair (norm(al) mode). So it is also possible to side-chain a mono signal from the stereo inputs.

    Then added a DC blocker on the inputs as in RMS mode DC on the inputs can do some weird stuff. The blocking can be switched between AC and DC. AC mode has a -3dB cutoff point at approxomately 20 ~ 40Hz (depending on the sample rate) and DC mode does nothing, The filter will only operate in the compression calculation chain, the signal chain is not being filtered.
  • PulseSync - A Pulse sync module Added a PulseSync module. The module gets triggered by an incoming positive edge on the pulse input, which it will then hold internally. When a subsequent positive edge appears on the sync input the output will be set active. Once the pulse got processed the ouput and the internal state are both being cleared when a negative edge is seen on the sync input. The incoming pulse is guaranteed to never get lost.

    This modue can be used to sync up a pulse event appearing at a random time to a syncing clock signal.
  • Transpose - A Transpose module Added a Transpose module. Four separate transposition amounts can be set each having an activation input. The output will be the input note value transposed over the sum of the active transpositions. Transposition range is -24 to +24 semitones.
  • SquareSineLfo - A Square and Sine LFO Added a SquareSineLfo module, it outputs a sine along with a PWM controlled square wave. I often end up clocking things with sine LFOs as sine are easy to multiply up to higher frequencies (using the ChebGen module) which is easier often than starting with a higher clock and dividing it down. Also the sine shape is more usefull to do (synced) modulations with. However its not easy to change the 'pulse width' of the sine, so that is what the square PWM is for, that one is easy to make changing note lengths for driving sequencer.
  • PulseSkip - A pulse skipper Made a PulseSkip module. It will pass on input trigger signals only when the input level is larger than the compare level. Levels are computed as the sum of the preset level (as made visible in the displays) and the modulation level. Once a pulse got started will only be ended when the trig input goes inactive, so either a complete pulse is being passed on or it is being skipped.

in version 2017.3.14.0

  • Bug in DataGraph module for the splines mode, it outputs X values instead of Y values. Using Y works way better - so that is fixed now. And its not in the AudioGraph module, as that one can not use splines – pwew :-)
  • Mode and range changes through selectors were not handled when controlled with the keyboard (only mouse clicks worked for that), fixed it.
  • Added an 'act' input for the EuclideanRhythm, SeqRandom, SeqRandVal, Pattern and ProbSequencer modules.
  • Added inv outputs on EnvAHD and EnvADSR modules, they output 1.0 minus the value that is on the env output.
  • EnvControl - An envelope controller Made a controller module for the DataGraph module to allow it to do envelopes. The help blurp says : A retriggerable envelope controller. The envelope will start when the trig input goes from zero, or below zero, to above zero. The output will then in the set Attack time go to the level set with the level control. When the trig input falls off the output will start getting larger again for the set Release time, till a value of 1 is reached. At every new trig start the ouput value is reset to 0, and the above cycle will restart. Both the Attack and Decay phase are linear, any non linearity is to be set in the controlled graph. This module is meant to control the GraphControl module, the actual envelope shape is then drawn in that module. The set level will then correspond to the vertical distance in the graph where the hold value will be.
  • SeqPattern - A pattern sequencer Made a pattern sequencer module to be used for drum patterns. When set at low speed it can also be used to control the time structure for a self playing patch.

    A full pattern is made from eight parts, where each part is composed of eight sections and each section has eight elements. This makes for a total of 512 steps, where each step controls 24 bit outputs simultaneously. The steps can be set to off, to pass the incoming clock, or to be on.

    For detail information please click on the module, or for some background information have a look at the forum thread.

    Sequences can be saved to disk and reloaded just like any module (or any group of modules) can - as a preset. Right click on the module and select load / save preset from the context. menu.

in version 2017.2.25.0

  • Range control for the pulses module was not working, fixed that.
  • Output signal type selection for the pulse delay module was not working, fixed that. Also tried to clarify the help text a bit.
  • Constant module when put into 'note' mode is off. And this seems to be wrong in more module types. Indeed it did affect the Constant, LUT and Knobs4 modules and it is fixed now. Also made it so that when 'notes' mode is selected the note controls have 128 steps now, and possiby some other number in the other modes. Also the LUT module was having an offset in the 'notes' mode, this got fixed too. These changes will affect old patches using any of these modules in 'notes' mode.
  • Made a Moog style 24 dB low pass filter. MoogFilter - A Moog
          style filter Inspiration came from here, the Huovilainen variation on the theme. I've found it to be a bit explosive … the volume that is, so made it to oversample a bit more and also added a saturation function (tanh) on the ouput, as it had a tendency to go like very loud when resonating. This is not a cheap filter CPU wise, but I think it to be a nice one with the built-in distortions. On the referenced web site there are some more variations, I may try some other and make a selector maybe for different types.
  • Made a fixed divider module. FixedDiv - A fixed divider The module has a series of outputs with fixed divison rates. After reset all the outputs will be off, to be toggled each time the number of input clock periods matches the division count for that output. The ouput will stay high for one clock period then.
  • Made a multiple waveform oscillator. MultiOsc - A multi
          wavform oscillator This module simultaneously makes a sine-, a trianglar-, a saw- and a square-waveform. The PWM input provides linear Pulse Width Modulation (on the square output only).

in version 2017.2.19.0

  • Delaytime range on stereo looper was not working, fixed now. Also changed the start and length control modulation amount knobs to be displayed as linear (they were actually working as linear controls already but not displayed as such).
  • Some screen painting took place on the desktop's device context, changed that to happen on the editor's context only. This draws better selection rectangles and better lines (on cable drawing). This may as well solve an issue with the screen not being repaintd properly (which was reported by someone using Windows 10). Also thickened up the lines a bit for better visibility.
  • Added inv outputs on EnvAR and EnvARRetrig modules, they output 1.0 minus the value that is on the env output.
  • MIDI transmit bug. The command was never sent only the data bytes … Fixed now. And of course I had forgotten to test some code …
  • Added f(x) = - x and f(x) = 1 - x funtions to the Monadic module.
  • Added a a modulation depth control module ModControl - A
          modulation depth controller . The graph illustrates it's workings (where the red signal is the wanted modulation depth (mod), the green signal is the modulation (in) and the blue signal represents the resulting output). For the inputs and the ouput the signal type can be set, for the graph they were set as in the mocule image. The mod signal and the ouput being unipolar and the modulation (in) signal being bipolar. I've made this module primarily for AM modulation (tremolo), but it would work for vibrato as well when applied to a PM input of an oscillator.

    The internal calculation used is : out = mod * ( in - 1) + 1, so that when mod = 0 the output will be 1 and when mod = 1 the output will be a copy of the in signal. This is being calculated on signals assumed to be positive only (unipolar), the input output type selecors are to be used to ensure such scaling. modulation depth controller

in version 2017.1.29.0

  • When windows screen magnifiction is set to something else than 100% everything on screen gets messed up. Turned off screen scaling, which paradoxically results in better scaling - I guess the scaling property on forms is a promise to windows ... anyways, windows will now scale all stuff properly - or so it seems.
  • Bug in LifeSeq module, the chain input does not work – fixed now.
  • Obscure bug in the wave file reader code, it would read more samples than present in the audio file which would cause glitches on playback. Fixed now.
  • Some of the 6 dB filters (the high pass parts) could produce denormals, fixed that.
  • Bug in multiplier module where the leftmost input would not work due to having a wrong name. Fixed that, but all patches using that input were not working properly and on reload will not restore the connection. When needed this can be fixed manually. Open the patch in a text editor, search for all occurances of the text 'multiplier_in47' and replace all of them by 'multiplier_in7', the patch would then load again as intended.
  • Bug on pasting modules. It looks like when a selection laarger than what is present in the current patch can not be pasted. This has to do with an internal naming conflict for modules. This issue must have been present for years I think, looking into it now. Is fixed now, it made the code somewhat simpler too :-)
  • Added a reverse input to the LifeSeq module, when active it plays from right to left. Also added stops to the module. When one stop is set it will play from the first column upto the row where the stop is set and it will then jump back. When two stops are set it will start in the column afer the leftmost and it ends in the column just before the rightmost. When the reverse input is active this gets reversed. When no stops are selected the full range will be used. On reset the cursor will jump to the column after the leftmost stop, unless only one stop is set – in that case it will go to the first column. This also gets reversed when reverse mode is active. I thinks the stops to be interesting mainly for the sequencer mode.
  • Changed MIDI NoteOn handling a bit. When a NoteOn with velocity 0 is received it gets translated into a NoteOff event. The velocity for the generated NoteOff was set to zero, it is now set to 64 instead. Changed that for the MIDI file player module too.

    Implemented running status for the MIDI transmitter, this was already present for the receiver.

    Updated the MIDI decoder and encoder to be able to handle RPN and NRPN data, so could make modules handling those MIDI messages now. Implemented a mode for this. When 7 bits mode is on the callback will be called when the MSB comes in, in 14 bit mode the callback will be delayed until the LSB comes in. When MSB and LSB get swapped by the sender it will still work, provided 7 bit mode is selected, as in 7 bit mode LSB reception will not trigger the callback (and the internal value gets updated anyway on both MSB and LSB reception.

    Data increment and decrement are implemented as well, in 7 bit mode they will change with steps of size 128 and in 14 bit mode with steps of size 1. Increments and decrements are clipped to the range [0 .. 16383] (which may get interpreted as a range [-8192 .. 8191] depending on the actual receiver), no wrapping takes place – could make a mode for that too though I guess.

    All this is in preparation for MPE (Multidimensional Polyphonic Expression) … going to be some messy fun that for what's basically a mono synth … sorry paraphonic :-)

    But first MIDI will need little more attention.
  • For PortAudio I've changed the way buffering is handled. It is now possible to set buffer size of zero, whech means that PortAudio decides on it. This works for ASIO as well. For legacy mode this is not possible, a 4096 byte buffer will be used in legacy mode when 0 was set. I've noticed that the WASAPI interface gives me best results for latency, but I've also noticed that I'll have to shave off some of the peak load for some of the modules to be able to use that for larger patches. I've added a buffersize display under the CPU load display to be able to see what gets actually being used (it shows the number of samples delivered and requested by the PortAudio callback). Setting the buffer size to zero may cause the VU meters of the main window to be updated a tad irregualr, but didnt actually really see that. Also, in the Debug Screen [F5] I've added latency indicators, they show what is being reported by PortAudio.
  • Processing for the LifeSeq module is spread a bit better over time now. After a change request was seen a column counter is set up which gets adjusted on every control rate tick. On each tick only one column of the automaton gets updated. As a consequence the updates should not occur any faster than once every 32 control rate ticks (SampleRate / ( 8 * 32) Hz). Also the display will now get updated only when there was a change.
  • Made it so that all MIDI sends from a patch on a channel > 16 are sent back into the patch itself (and the channel is decremented by 16 then). This makes it possible for a patch to send MIDI data to itself by allowing it to send on a channel > 16. For the MIDI send modules these channels can be selected as ic 1 to ic 16 (ic standing for Internal Channel). The MidiNoteOut and MidiCCOut modules now allow for such channels to be selected, so a patch can now send notes and CC messages to itself. Ssuch MIDI messages will be handled internally in the synth patch and will not be visible outside it (like in the user interface, or in the outgoing MIDI stream).
  • Two new modules, a Phasor Phasor - A Phasor and a painted waveform thingie, the AudioGraph module

    The Phasor was created to control the AudioGraph, but it can also do phase control for oscillators.

    The AudioGraph is better suitable than the DataGraph module for audio rates as it AudioGraph - A painted waveform module internally uses Differentiated Parabolic Waves to reduce the aliasing a bit. I've added an auto scaling feature which after every data alteration rescales the graph to use the full Y value range. This feature can be turned on or off.

    Also added an input to randomize the graph, randomizition will occur when the random input goes from zero or lower to something greater than zero. The actual momentary value at that stage is used to control the amount of random to be applied. Small amounts (near zero) of random cause the graph to be changed just a bit, a value of one would create a totally uncorrelated new graph. Unfortuanately the rnd input acts sluggish … maybe something to fix later on.
  • Added a tilt filter from here. TiltFilter - A tilt filter A center frequency can be set for it and a tilt factor for the frequency response line. With tilt in the mid position thre will be no filter acction, turn it up for more highs or down for more lows in the output signal. The center frequency is the point the response line rotates around. The maximum tilt is ± 6dB / Octave.
  • Song - Song module Added a txt end output to the Song module, it will fire when all phonemes are spoken. It will not fire initially so it can not be used to make the module self looping. However, the module does have a loop mode for that purpose. I've added it to be able to only start the module when it was not already running (with an RS flip-flop added).
  • Demux - Demux module Added hold mode to the Demux module. When active XFade will no longer work and outputs will keep their value when they get muxed out (integrated sample and hold). The new button toogles between cross fade and hold modes.
  • RandomWalkLfo - RandomWalkLfo module Added a sync output to the RandomWalkLfo module. The sync output goes active when the output values change and it goes inactive halfway the LFO period. This so I can get triggers at the LFO rate. Also added an output smoothng mode to this module. When smoothing is off a stepped wave is produced, when it is on the wave glides from old to new values. And also added a distance modulation input.
  • Value - Value module Added a maximum value display to the Value module, it will display the maximum of the absolute value seen. A reset button was added too to be able to reset the maximum to zero. Also a patch reset will set the maximum value to zero.
  • Changed ini file loading a bit, at first Wren will try to load an inifile based on the name of the actual executable file name. When such does not succeed it will try to read a file 'wren.ini' from the same folder the executable is in. This assumes Wren originally will be called 'wren.exe', but makes it possible to have a copy of the executable under a different name which will then try to read the original settings (but they will be saved into an ini file named after the actual executable fiel name). Anyway, this should make it a bit easier to have two (differently mamed) Wren executables in the same folder, and to have the new one to initially inherit the settings of the default one (they can be set to differ later on). The looks will always be shared.

in version 2016.10.23.0

  • Oops ... a bug in the AM modulator causing an addressing error, fixed now.
  • I've changed the implementation for the intdif module a bit. For the integration function the output value is divided now by the execution rate of the module. This can be scaled with the gain control slider, but it means the output will be way lower than it used to be. Likewise for the differentiation function the output value is multiplied by the excution rate, and this is also scaled with the gain slider. This results in way more output signal for the differentiator. Also the output values for both integrator and differentiator are clipped to a range [-10 .. 10] (this used to be the case for the integrator only). The execution rate depends on the set sample rate and it can be either control rate or audio rate depending on the rate of the input signals.
  • Markov - A Markov chain module Trying my hands on some Markov stuff. Not sure if I can get the learning mode fast enough for real time use, playback should not be a problem.

    This is a first order implementation.

    The internal state consists of a number of nodes each holding some value (for which a maximum must be set with the max size control), a State variable holding the current node index (which is not under direct user control) and a matrix of transition chances (which is not under direct user control).

    When the learn input goes active the current input value is looked up in the nodes, and when found the transition probability from the previous input value to this new one will be increased with the current strength value (which can be negative). When the new value was not found it will first be appended to the node list. When the node list becomes full and the mode is set to 'once' an overflow condition occurs and the new transition will not be learned (also the Ovfl light will go on then). When the mode is set to 'cont' no oveflows will occur but the oldest transitions will be discarded instead.

    When the 'new ouput' input goes active the current State variable will move to a new one, this is a random process controlled by the transition chance matrix.

    The state of the module can be saved to and loaded from a file (must still implement some user interface for that), so … training could be done in non-real time mode when the need arises. Anyways .. let's test things first – actually it does not seem to perform so bad, great :-) It will depende on the input material, when there are many different values things may be worse, but for discrete events (like note values) it seems all fine.

    Now it needs to be made a bit leaky … as currently when the input patterns change it will take longer and longer before those new patterns will be learned. Although setting random strength values seems to help here – just like setting not too many nodes and using 'cont' mode.

    Now working on some code to do do the Markov thing a bit more efficient so I can hopefully implement a second order implementation which is fast enough for real-time learning.

    Ok, that seems to work. It also seems to be not too hard to generalize it a bit to arbitrary orders. I've implemented something, but found no time yet the check the workings or the the performance.

    After a little break and some bug fixes … arbitrary order seems to basically work, it needs more testing though.
  • Filter6dB - Another 6 dB/ Oct flter Made a variation of he Average filter with direct frequency control (instead of just exposing alpha). The set frequency references the - 3dB point. Filter falloff is 6 dB / Octave, just as for the Average filter. The filter should work on control and audio rate signals (Rate Smart).

    Filter6dBBP - Another 6 dB/ Oct flter Made a bandpass variation on this and then made a stereo verson of that one too. I've used this one on the final output of a patch to trim off excessive lows and highs a bit.

    Filter6dBBPS - Another 6 dB/ Oct flter When in control rate mode the frequencies are off by the control rate decimation factor (currently 8), the displayed value being too high. I should fix that by displaying the lower frequencies, but as of yet there is no proper mechanism for that.
  • Added a new tab for generators (gen) and moved some of the 'sequencers' there. This tab is meant to hold modules to be primaraly used for generative music. So state machines, song generators, cellular automata etc. Moved some modules from the control tab to te new tab as well.
  • CellAut - A simple cellular automaton Automata … well … just one automaton for now, but will likely make a couple more based on the same underlying engine. This one is a rhythm generator only.

    This module implements an 'elementary cellular automaton'. Each cell can have a value of either zero or one. Three cells are evaluated according to the set rule and this will yield a new value for a next generation cell. The rule number [0 .. 255] is being interpreted as a bit pattern which is indexed by the three bit pattern generated from the three evaluated cells. This is all according to Wolfram's theory about elementary cellular automata. The start state of the automaton consists of one single cell having a value of one.

    With the steps parameter you can set the number generations to be calculated, this results in a bit string. On every step a next bit will be sent to the output and when the end of the string is reached the sequence will wrap back to the beginning.

    The Faults parameter sets the average number of cell faults generated for each new cell calculated. The set number is divided by 10,000.

    The total length of the generated pattern increases with two on each new evaluated step, which results in length = 2 * steps + 1, which is odd always. The reset input can be used to wrap back sooner.

    The blue output has a weighted sum of the last three bits ( Bit[ anIndex] + ( Bit[ anIndex - 1] shl 1) + ( Bit[ anIndex - 2] shl 2)) / 8.0. The dir input when active reverses the play direction.

    Some rules will not generate any output at all (like rule 0 or 255), some will generate simple repeating patterns and others willl be almost random. For some rules the steps setting may not change the sequence much, for others a next step may differ wildly from the previous one.

    For some ideas about possibly interesting rules have a look at my rules page. At some stage I may build some of the visulas into Wren , but not at this stage. That page, at the very end, also shows an implementation of the algorithm being used.
  • LifeSeq - A 2d cellular automaton And another cellular automaton based module. This one uses Conway's game of life. the curent help text says (subject to change though):

    A Life based sequencer. Based on Conway's game of Life, but there are some extra modes selectable from the mode selector. The step input moves the cursor, which will put the cell values from the curent column on the green outputs. The change input triggers a new generation of live cells, according to the currently selected rule. The blue sum output has the column sum of the cells under the cursor, this can be a binary sum or a linear one. The grid can be set to be wrapped or unwrapped. In wrapped mode the top connects to the bottom and the left side to the right. The fault rate parameter determines the amount of faults made in applying the evolution rule. When the number of cells drops below the low count the grid will be filed with random values, the chance of a cell becoming alive is set with the rnd amt parameter. The rnd button will fill the grid with a random patttern, obeying the rnd amt setting. The clr button will clear the grid, this usually will then immediatly set random pattern as the live cell count drops below the minimum. It is possible to draw on the grid, a single click will toggle the cell state, with shift cells can be turned on and using ctrl instead will turn cells off.

    Using a right click on the grid the current state can be saved to or loaded from a file.

    This a a pretty big module, and 32 rows seems a bit much maybe, but I've found the game of life to be more interesting on larger grids. The current 32 by 32 size seemed a minimum for interesting patterns to occur. And at the same time 32 logic outputs seems like overkill as well, for the sum output it's a nice amount though (2.5 octaves in the note modes).

    Made an inhibit control on the change input to be able to stop rule evaluation, and also made a 'Freeze' mode (in addition to the various ;ife modes) in which the current attern will not change – this allows for painting sequences.

    Now if only I could get the module to load itself from a patch file … it would then double as a 32 x 32 (event) sequencer (the sum output can be set to make note values though) … it also reinitializes on every module insertion or deletion … which it should not do. But otherwise it seems to work well. Ok, the save and load stuff works too now, but the mode has to be set to 'Freeze' for this to work properly (or else the internal Life machine will have it's own ideas about the pattern).

    The new grid control thingie could be nice for other modules as well :-)
  • When Wren is closed the current patch will be saved in the application's home directory (where wren.ex resides) as '__l__a__t__e__s__t__.wren'. This file can be reloaded from the file menu trough the 'Load last patch' item. For just in case … This is not saved in the most recently used patch list (unless you manually open it; it will not be opened automatically on Wren startup).

in version 2016.10.2.0

  • Added the Markov module, but it has not been fully tested yet, see remarks in the 'working on' section above. Also I did not implement the code for saving and loading models yet – or rather – I did, and then the code changed, so it needs to be done anew.
  • Delay module, in 'short' mode, does not get correctly initialized on patch load, it seems fine on patch recompiliation though.

    Or actually … several parameters were not updated in the synth after for instance a range change on a mixer or when clicking an rnd button on a sequencer, etc. etc. Fixed that, it was introduced with the randomization features in the last couple of previous releases.
  • PerlinNoise - Perlin Noise Made some new noise modules with Perlin like noise, in which the roughness can be controlled and the pattern length. A clocked one and a free running one. New noise values can be inserted to change the pattern. The maximum pattern length is 4096, the length controls set a fraction of that. The number of layers can be set, more layers give more smoothness, at the expense of processing time. The new input when PerlinNoiseTrig - Clocked Perlin Noise unconected is active, giving noise like behavior, when it is set inactive the behavior is tone like. When made active less frequently it will change the timbre. I'll probably make LFO versions for this too, welp, would like to at this time, it seems like a slowly clocked one can make nice percussion patterns. Also I'd like modulation of the length – ok, added that. Not sure how stricly Perlin this is, I've tweaked the interpolation function from one layer to the next to more or less give the same amplitude for smooth and rough settinging (but it is random of course …).
  • With the above … there now are 200 module types.
  • PerlinTone - Perlin noise in tone mode And then when on the Perlin you do not set new values very often it makes sense to have frequency control as well. The maximum sequence length was set a bit shorter for this one (256 vs 4096 for the Perlin noise modules). This can make some nice metallic or tone like noise sounds. I should add a button to the Perlins to invert the new input. As it is now the new input is set by default, this is not always handy.

    I've added the invert option ( i(nvert) vs n(ormal), the latter being the default value on the noise modules, the former for the tone module).
  • RandomScale - A scale randomizer And another new module, Random scales … the help blurp says something like:

    This module implements a scale randomizer. Each time the rnd input goes from inactive to active, or when the rnd button is clicked, a new random scale mapping will be computed. A scale will always have 12 notes per octave, and all octave mappings will be the same (with an octave shift, of course). Within an octave the 12 notes will be randomly mapped to 12 (probably, but not guaranteed so, it's random after all) different notes.
  • Arpeggiator - A simple arpeggiator A simple arpeggiator

    On each clock on the 'new in' input a new input sample is is taken and added to a list of samples, the oldest value present will be dropped from the list then.

    This list can be left unsorted, it can be randomized or be set to play the lowest or highest note first .

    The list length is set with the length control.

    On each output clock on the 'new out' input the next stored value from the sorted list will be output.

    In random mode the order in the sorted list will be randomized when the playout wraps back to the first value.

    In unsorted mode the playout will be the recording order.

    On the input side an acceptance filter can be applied. All incoming values can be accepted, values differing from the previous value or values not present yet in the list of samples.

    The toggle input when inactive causes the selected sort order to be in effect and when active the next sort order will be used. This can be used to toggle between low to high and high to low modes, for instance.

    When there are not enough input values available (yet) arbitrary values will be clocked out until the playout counter wraps back to zero.

    The reset input (or a global reset) will cause the playout pointer to be set back to zero without changing any stored values.
  • ProbSequencer - A probabilistic sequencer And another new one, a probabilistic sequencer.

    For each note the probablility with which it will be played can be set with a slider (and this value can be multiplied by the value on the associated input). Notes have to be be enabled before they can sound, and note enables can be selected from a scale preset.

    The presets will be dynamically loaded from a file wren.scale that must be in the same folder as the Wren executable file. When this file does not exist Wren will create it. After that you can edit it with a text editor (like Notepad for instance) and Wren will not touch it anymore.

    A selected scale can be altered with the note buttons, and such a change will be saved with the patch (making the shown scale preset name meaningless, of course).

    The rnd button will set a random probability distribution, the clr button will set a flat distribution. The distribution can be altered with the tilt control. A zero value means that there is no tilt, a positive value maked higher notes more likely to be selected and negative values will produce more low notes.

    A transposition can be applied to the selected scale with the trans(pose) control. C is the 'neutral' base note (not leading to any changes). Transpositions are not reflected in the shown note pattern. The low and high note controls limit the range of possible notes.

    The sm(oo)th controls determine the likelihood that the next random value is about the same as the current one. So with a larger smoothness the results will be less jumpy.
  • Added noise type selection to various noise modules (OSC and LFO). The default type is Linear (which was the only available mode bfore), the added types are Gaussian (with a fixed sigma of 1.0) and exponential (with a fixed lambda of 3.0). This affects the Noise, NoiseTrig, NoiseLfo and NoiseLfoTrig modules, but backwards compatibility was maintained.
  • Pattern - A pattern generator Added mode control to the Pattern module. A mode can be set on each step, it can be normal (nrm), random (rn1), weighted random (rn2, or rn3) or skip. Normal meaning that it will do it's full count. The random modes will generate a random number [0,Count] and use that as the step count. The first random mode considers all numbers in the interval, the second random mode only divisions by 2, and likewise rn3 uses divisions by 3. Skip will just skip the step. Also added individual step outputs which will go active when the associated step causes an output pulse to be made. The step outs will produce a 'per step' copy of the main output.
  • Added clear inputs to arpeggiator and poetry modules to allow them to forget stuff. These are latching inputs capturing a low to high transition. When they are in the set state a next value to be clocked in will not be the input value but zero instead. After having been processed the set state will be cleared.
  • AmMod - An amplitude and ring modulator Added an Amplitude / Ring Modulator module, which is a multiplier with control over modulation depth and modulation offset. This makes it a bit easier to apply less than full depth AM or RM to a signal. The input signal type can be set, and it can do a fade between amplitude modulation (AM) and ring modulation (RM).
  • Rewriter - A pattern rewriter module And made a simple pattern rewrite module for which a couple of rewrite rules can be specified, and an expansion level. There is a small alphabet of the letters A, B, C, D and E. For each letter a substututon is specified in terms of other letters from the same alphabet. For instance, given the rules:

    • A → ABC
    • B → C
    • C → D
    • D → AC
    • E → B
    Then a number of expansion steps is speciefied resulting in patterns being generated from the start symbol 'A'. With the rules above the successive patterns would be:

    • A → ABC
    etc. The maximum depth to be set is 8, which would result in a pretty long pattern already with the rules above.

    At each positive input step a next symbol from the generated pattern is selected and the corresponding output will be made active. At the end of the pattern it will start again from the beginning. Some rules (or all) can be left blank for simpler patterns. All letters must be from the set [A..E], everything else will be ignored for pattern generation.

    This is after an idea found at RobotPlanet, which in turn references this article.

    Decided to generate all 8 expansions whenever the rules change, which made it possible to have depth modulation – which I've added.
  • RewriterNote - A value generating pattern rewriter Made a variation on the previous module generating values instead of events. It also has a couple more rules to compose with. It adds a lookup system so that for each active step a value is put out. The value knobs are mode controlled, one of the modes being 'note value'. There are the usual dB and linear ranges too.

    A common chain input is avilable which is simply added to the curent rule based value, and then there are individual rule chain inputs which are added to the ouput only when the corresponding rule is active – with this the module can be used as a rule based multiplexer too (when all values are set to a neutral C4 or to zero, depending on the selected mode).
  • TuneSmithy - A fractal-like note pattern sequencer A TuneSmithy module. This is a melody generator after an idea by Robert Inventor and it is explained here. The sequence can be arbitrary long in principle, but decided to cap it at 1024 steps. The pattern is a comma separated list of integer values. The second link above explains the inner workings.

in version 2016.8.21.0

  • When during live morphing new modules are inserted some odd stuff happens. Ok, only when the module does odd stuff, see next item – the GVerb module would crash. Ah, and modules get set to all zero values when inserted while live morph is active. Aha optical mostly … the first variation gets set from the default knobs and all other variations get set to all zeros, which looks confusing in a live morph situation. Still it would be better that on insertion of a new module all the variations would be be set the same – according to the default knob positions. Ok, fixed that.
  • Live morphing when the GVerb module is present sounds bad (even when it is not being morphed), for FreeVerb it is fine tho. Ah, it was being recreated all the time even when the parameters did not change, and then it would crash. Ok, fixed it. But there also is the issue that automation will change parameters that it should not change. Ok, stopped that too.
  • Bug in DataGraph where the rightmost point would always end up top right (1,1) even when it would not be drawn there. Fixed.
  • The active variation randommizer got mixed up a bit with the randomize function from the morpher, unmixed that. The active variation randomizr is selected from th e action menu or by pressing 'R' on the keyboard and it sets random values for the current variation only. The randomize function for the morpher sets random values for variations 2 to 6 (for quickly generating a handful of new genes).
  • Bug in ScaleQuantizer, the selected scale selection is not properly read rom a saved patch, the buttons are OK though. Was an issue for all dynamic count selectors and got introduced with the introduction of variations. Fixed now.
  • Oopsie .. the filter inversions used '-' for 'off' (which can not work anymore after some changes on how dashes are handled for popup menus in relation to automation) changed them to '.'.

in version 2016.8.20.0

  • Tod - Time Of Day Made a Time Of Day (Tod) module which is a saw tooth LFO with a period of 24 hours synced to the local PC clock. So at 00:00 it's output value will be zero and at 01:00 it will be 1 / 24. The clock has millisecond resolution. The output value may drift a bit as windows does time syncs when it feels a need – but it will be the best estimate of the current time. A couple of level shifters and ChebGen modules could be used to obtain signals that run faster. Like first make the signal bipolar, then multiply by 24 (first by 12 then by 2 using two ChebGens in saw mode) and then level shift it again to unipolar positive to get a signal with a rate of one hour. Then the same trick with a factor of 60 to get minutes, 60 again for seconds.

    Hmm … instead, I've just added a couple of outs for hour, minute and second.
  • Made a new option for the morpher, it can do a live morph over the breeder too now. Normal morphing is between the left and the right morph and morphing over the breeder uses all eight variations present in the breeder instead (when the breeder is morphed with the Morph botton this is equivalent to the non breeder morph, but when mutate or mate is applied variations will be introduced). This new option tends to (depending on settings and actions) give more lively morph results (like for the XY controls the dot can then move in a rough curve instead of in a straight line only).

    soapy worms And made a new 'soapy' worm shape – how cruel it now seems to hold them in a cage like this …

    I've turned the morpher code inside out a bit, that is, I've made variations for patches and based the morpher on that. Variations are stored with the patch, so they will still be there after patch reload. As the variation values are stored in the controls (knobs and such) now, this also means that module additions and deletions do not mess up the the the worms for other modules anymore. All this needs some work though still; the worms are not always updated correctly, and there is an issue with XY controls loosing data or something – but it stopped crashing at least :-)

    Changed the randomizer as well, it now works through the same mechanisms as used by the morpher. It will set random variation values for the active variation now (which then in turn moves the knobs, the randomizer used to work on the knobs directly (which would then change the current variation)). It is all a little easier this way. Anyway … some more work to do on this.

    Most stuff is working now, but drag-drop of worms is messy still … some more work …

    But it's not working well; turning some more stuff inside out – the mutations are all carried out on the patch now and then update the worms, instead of working on the worms and updating the patch. Let's see what surprises will arise from that …

    Ok, that goes better, it seems to all work now as it should – except for it being very slow all. Not sure if its the editor updates or the worm updates … there aree a lot of params that change on a live morph … more work :-)

    Improved the speed somewhat, still not very fast, but it will do I guess.

    Livemorphs are controlled trought the lights update routines, that is not ideal (as the tempo goes all over the place) and this should be changed. Ok, changed that, it is currently updated at a rate of 10 Hz triggered from the audio generaton rate (and so independently of the lights update rate). So this should work properly for recording to disk as well. The exact rate may change later from 10 Hz, not sure yet, or make it a user pref maybe.

    Live morphing works over the variations now, and I've removed the left/right morph worms. When a left/right morph is wanted you can do a morph operation on the breeder, then copy the worms to the variations and then perform th elive morph. So with less options the same functionality is still available.

    toobar with variations Added a couple of buttons to the randomizer / morpher screen to make copying easier. Drag / drop now works properly as well. Moved the live morph options from the randomizer to the main toolbar – turn auto mode on or off, and the morph control knob. Morphing no longer changes any variations, instead there now is a temporary variation which is being used.

    Changed some keyboard shortcuts related to the randomizer / morpher and added some for variations:
    • R - randomizes the patch (was Ctrl+Shift+R).
    • Shift + R - toggles the exclusion visibility. (was Ctrl+Shift+Alt+R)
    • Alt + R - shows or hides the randomizer window.
    (Ctrl+R still is recent patch reload).

    For changing variations you can use the keys 1 … 8, or they can be selected by clicking on a worm in the toolbar or from the View menu. Variations can be dragged from one spot to another, or even from or to the randomizer window.

    Made it so that it is still possible to see all of the toolbar in the space needed for four horizontal modules … which is like 1024 pixels. This would be a practical minimum value for the horizontal screen resolution needed for Wren (see image above). And also added the mutator commands in there (as well as into the action menu).

    Had to change the patch format again … not really for the variations, but could not store the active variation with the patch in the current format. Made the format a little more flexible again, so that future patch parameters will not need a new patch format (which already was the case for control and module parameters). Anyway, it's backwards compatible, but not forwards, as in: old patches can still be read.
  • Auto - Auto-randomize, -mute, -mate or -morph Made an Auto module which can perform Auto-randomize, -mute, -mate or -morph in the same way the buttons in the randomizer / Mutator window do. Making this a synth that can truly auto-mate!
  • The '-' avoidance code has a bug it seems … causing Wren to hang in an endless loop on some patches when the randomizer is used – investigating. Ok, solved that, but still saw dashes on morphing … fixed that too.

    Which … of course … introduced an issue for selectors having only two values and no dashes at all, fixed that too.
  • The PitchShift PitchShift - Pitch shifter module can not support randomization on the delay parameter. I disabled that. The problem is that when delay and shift are changed at the same time invalid internal values can occur. All automation has to be and was set disabled for that knob.
  • When a control was set to be non-randomizable, or non-automatable actually, and in the patch it was stored to allow for randomization the red exclusion rectangle would not show. Fixed that, and when such a patch is saved the control will be saved as non randomizable too.
  • PitchShift module would produce denormals under some conditions. Probbly fixed it with normalizing the linear interpolation code's output.
  • Gabe made some new bitmaps for the looks. I've made some new omes too — had a lag of about 40. Looks file got updated to 2016.8.2.
module glyphs randomizer

in version 2016.7.27.0

  • Fixed the patch randomizer for selectors having '-' values (these are meant to generate separators in the associated popup menu). Trough the menu interface such items can not be selected, but the randomizer found 'm allright …

    Ah, and clicking on a selector or using the cursor keys or the space bar hits them as well. Fixed that too.
  • Made the Pad, Spiral and DataGraph modules randomizable.
  • I'm working on a patch mutator, it's very much like what the G2 has. Still some quirks to iron out on that, like what to do when the patch gets modules inserted or deleted. The current implementation does not handle that as it should. Also the images seem to not always be drawn correctly. Ok, found the issue, I'm misusing, sort of, some selectors as indicators (on the ScaleQuantizer). This means that the chord selector has to be disabled for randomization. It should maybe also indicate that the key selection does not map to the selected chord anymore. But then again … I could just consider the selector to be a preset selector only, not reflecting the actual state. On a patch reload the actual keys will win anyway. I may change this when i get ispiration.

    I've made a FAQ entry for the morpher / randomizer.

    The forum thread is here, it may have some info not listed here.

    Made the mutator work for Pad, Spiral and DataGraph too. There are some issues with the DataGraph, as points can be added to or removed from it. This means that the number of data points present in the mutator may change. What I did for now is that such a situation is detected and the mutator will be re-initialized (which looses all the current worms in the mutator, making a random set of new ones, and the scratch area will be cleared). Module insertions and deletions are handled in the same way.

    Added two extra worms to the mutator, a left and a right morph, and a knob to fade between these two. Also added a modulation option to the knob, and a new module which can do the fade from the patch. This works at the lights rate, which is user controllable, but it can not be very fast nor can the exact timing be very predictable, as a lot of screen updates need to be done. Still for slow morphs between two variations it would be nice. It is possible to have more than one LiveMorph module in the patch, but things may get a bit jumpy with that.

    The randomization exclusion works for both the randomizer and the mutator in the same way. There is a keyboard shortcut to visualize the exclusions, and also when the randomuzer / mutator window is active exclusions will be made visible in the patch (with red rectangles around the excluded controls or modules).
  • Made it so that when patch randomization is requested (as opposed to single control or single module randomization) and there are no modules selected, that all (randomizable) modules are randomized.
  • Changed some code for the components introducing a couple of interfaces for them: IAutomatable (for MIDI control), IRandomizable (for plain randomization) and ICollectable (for controls that can contribute to the genome used for patch mutation). This makes things a bit easier to program, I hope … it was quite some work. Please note that non automatable controls can not be randomized either. In general anything that needs patch recompilation can not be automated or randomized.
patch randomizer / morpher

in version 2016.7.23.0

  • Reverb - Reverb Made a scale control for the Reverb module. It sets the internal length of the delay lines to some factor of the original length. This alters the color and buzziness of the reverb. As the lengths of the internal delays are modified a change of scale needs patch recompilation( e.g. a change causes a brief silence).
  • EnvAHD - AHD Envelope Added an End Of Cycle (EOC) output for the AHD and ADSR envelopes. When fed back into the trigger input turns the envelope into an LFO, but can it be used to chain envelopes as well such that one triggers after another.
  • Moved the Constant, Amplifier and Ratio modules to the Math tab. This distributes the modules a bit more evenly over the tabs.
  • Working on a patch randomizer. Randomization is possible on Knobs, Sliders and Selectors. It is possible to randomiz a single control, all controls on a module, or al controls on a selected set of modules. There will be options to dissalow randomization on selected modules and on selected controls. The action menu will get an option to make visible the modules excluded from randomization.

    Made a randomizer control wimdow to make it possible to exclude module types and control types, partly by category.
  • For the randomizer I had to change the patch format to allow for a new module parameter type. Old Wren patches can still be read by the new Wren but new Wren patches can not be read by old Wren versions. I did make the change in such a way that in the future it should be possible to add new module parameter types without altering the patch version. This already was the case for new detail (knob etc.) parameters. Old Wren's should then just skip the paramaters they don't know about.

in version 2016.7.4.0

  • popup menu for DataGraph / DataMaker Made a popup menu for the DataGraph, or for it's DataMaker component rather. Some wave shapes can be selected and some basic operations on the data can be selected. With the symmetries there are some duplicates in the operations, like a Bell shape is the same as a vertically flipped cosine, and for the squares there are some duplicates as well. Added load from file and save to file to the menu. Added a left — right adjustment feature as 'make loopable' to the context menu.
  • MixMS8to1 and MixM16to1 were not working without modulation signals being connected, fixed that.
  • The timer controlling the lights and VU meter updates is started in running mode. When the startup is slow for some reason this may cause the VU meters to be updated from non–existing objects. Fixed that by disabling the timer at startup, after each patch compile it was turned on already, so things should be all fine once an actual patch is present.

    Decided to make all timers inactive during startup to enable them only in FormShow or even later — when needed. Also typed some extra checks around the VU meter calculator objects to see if they were allocated before being used.

    MIDI TX messages were logged from the audio thread directly (when logging was enabled), which was a bug. Fixed that.
  • Error in DataGraph module. It was meant to react to double left clicks or ctrl+left clicks by adding a new data point, but ctrl+double left click would add two points and would then mess up the order of the points. Fixed that and checked at other places if such a problem could exist elsewhere – did not find such places though.
  • There is some debug stuff left in the looper module (like the light), this should be removed once the thing gets settled … which currently it is not.
  • Delayed help file creation a bit so that the looks are completely set up before the images are being created – image previews on the module selector look better now.
  • Made the trigger LEDs for the envelope modules light up 125 ms always, even for very short trigger pulses. Some more will follow as some modules output very short trigger pulses that could not been seen on all input lights. This also means that for a non changing input signal the light will go off after a while, it will only show the trigger moment. made an error in this making the sample and hold turn into a track and and hold … and fixed that again.
  • It may be the case that there is a denormals issue for the Formant2 module, running some debug tracking on that, but lost focus … focussing again … After 10 or 11 hours of runtime on a patch, yup, got a denormal report, looking into the why now, it is on the output signal, should not be possible inspecting the code, odd.
  • Restyled the module documentation a bit and added a link to it in the main menu of this page. Also for newer modules I started to add links from the module images in this page to the documentation page (meaning that module images here are clickable now). Also fixed some inaccurate help text.

    I've started using a mark–down processor for easier markup of the generated help file. See the Acknowledgements section for more on this. This will allow for clickable links in the help, better looking lists, etc., Expect more help restyling.
  • Changed some things for popup menus. They should now popup near where the cursor is instead of near where the top–left of the control happens to be. Also in the patch editor I've made the menu key work for the element the mouse cursor is on.
  • Moved wire toggling and wiggling from the edit to the action menu, keeping the same shortcuts (Ctrl+space bar and Ctrl+W)
  • MixQS2to1 - Quad stereo 2 to 1 mixer MixQS1to1 - Quad chainable stereo 1 to 1 mixer QuadPan - Quad panner Made three new mixer types MixQS2to1, MixQS1to1 and QuadPan (which actually is a panner, but it's on the mix tab …). Although these do have blue connectors they are intended to be used for audio mainly and when audio signals get connected the connectors will change to the audio rate color. The panner uses an equal power distribution only. The mixers allow for 24 dB of amplification.
  • FastToSlow - FastToSlow converter Made an audio to control rate converter, which can be used to keep large areas of a patch from becoming red.
  • LfoTrig - Retrigger option added to LfoTrig Added a 'retrig'(ger) option to the LfoTrig module. When set into retriggerable mode and when the trigger input goes inactive and active again during the current pulse train the module will be reset to start the train anew. The default setting is 'normal' for compatibility with older patches. Together with the DataGraph module this could be used to make retriggerable arbitrary envelopes, for instance. Hmm … not quite … anyways …it seems useful … maybe.
  • Added a Polar Polar - Rectangular to Polar conversion module, it translates rectangular coordinates into polar coordinates.
  • Added a Rectangular Rectangular - Polar to Rectangular
          conversion module, it translates polar coordinates into rectangular coordinates.
  • StereoLooper - A stereo looper thingie Made a stereo version of the looper. Igt still has the drawbacks of the moneo one, but really wanted stereo.
  • Added a Spiral module, an experiment really. Per spiral winding of mouse movement a settable amount of note steps is added. Along the positive X axis the white places correspond with the steps. As this internally works with polar coordinates I made outputs for the angle (phi) and distance / radius (norm) as well. The len output Spiral - Spiral controller represents the spiral length for the current (X,Y) location (from which the note output is calculated). So at least it doubles as a Polar sort of Pad module. (But the latter can also be done by adding a Polar module after a Pad.)
  • Added an unattenuated frequency control input for the Lfo, SquareLfo and RandSig modules. This makes it easier to add overall speed control to a patch.
  • Added an MConst module for selecting some more or less often used mathematical constants, like 1, 2, e and 𝜋 etc. MConst - MConst for math constants
  • Added a 'wrap' mode to the DataGraph module, the standard behaviour was 'clip', which still is the default. In clipped mode an out of range input value will clip on one of the graph edges and in wrapped mode it will wrap around and come in on the other side again (modulo operation).
  • Monadic - Monadic function Added f(x)=x·𝜋, f(x)=x·2·𝜋, f(x)=x∕𝜋 and f(x)=x∕(2·𝜋) functions to the Monadic function module. Also added f(x)=floor(x), f(x)=round(x), f(x)=ceil(x) and f(x)=abs(x).
  • The Pad and Spiral module did not set their output values after a module load or patch change, it needed a movement first – I've changed that. I may have thought this to be a feature for the Pad module, but for the Spiral it was just a plain bug.
  • Removed all the all-too-obvious email addresses from the web page and documenttion.
  • Removed some unused stuff here and there from the code, making the executable a tad smaller.
  • Added some volume damping around patch recompile operations, the worst of the recompilation click is out now.
  • I've made an option to disable automatic doc file generation. This option is off by default (so docs will be generated out of the box), and this feature will only work when you use the old wren.ini file, e.g. when you copy the new executable over the old one (or copy the old ini file to the new location). You can always manually generate documentation from the Settings Screen [F3] by using the 'generate documentation ...' button there. Note however that when no docs were generated the popups from the module selector will not show a module, or an old version of the image.
  • I've added commandline passing of a patch file name. You can now associate Wren with '.wren' patches in windows such that double clicking on a patch will open it in the Wren instance that got associated. It is still possible to run multiple Wren instances, but they will have to run from different directories now, and patches opened through the explorer will always open in the associated instance. When starting Wren directly it will still open the last patch it had loaded as well. BTW it is possible (it has always been) to copy patches, or parts of it, from one Wren instance to paste them into another) or into a text editor, or whatever program that will accept text.

in version 2016.6.5.0

  • Changes in text controls and data graphs marked the patch for needing recompilation which was overkill. It should have been marked for change only. Changed that, and internally renamed some 'PatchChanged' stuff into 'Recompile'.
  • While all modules seem to be properly execution locked now during heap operations the patch as a whole was not locked. Changed that.
  • MIDI CC assignments to knobs are not working properly – CCs move the knobs alright but the synth value is not changed. Ok fixed that, but now on very fast MIDI I'm getting all kinds of memory issues. Ok, that actually is due to some errors in MIDI transmission – it was doing memory allocations from the audio thread. Ok, four bugs fixed in this … messy, but fixed now.
  • Added exponential FM control to looper. Oh that it was no longer clicky was a mistaken observation, with long loop times or record being off it is not too noticeable maybe. And a remark about the interpolation mode, all pass mode is not to suitable when the interpolation point moves relatively fast, that is for largish modulations.

in version 2016.5.29.0

  • The CubicClip module could generate denormal values for small hysteresis and alpha values combined. Fixed that.
  • When a text editor popup appears the wires of the patch will now be temporarily hidden, and once the editing is done they will be set back to the state they were in when editing started. This solves the problem where text to be edited was not nicely visible when wires happened to run over it.
  • I've changed the Normalize function to now filter out denormal values, small values, inf's and NaN's. Like:
      function  Normalize(const aValue: TSignal):TSignal;
        TWordArray = array[0..3] of Word;
        PWordArray = ^TWordArray;
          (((PWordArray(@aValue)^[3] and $7ff0)-$10) >= $7fe0) or
          ( Abs(aValue) < NORMAL_LIMIT)
        then Result := 0
        else Result := aValue;
    This does add a little extra run-time overhead - but less than 1% or so on a 90% patch. The NORMAL_LIMIT value is at -400 dB, TSignal is a Double.
  • Made text changes mark the patch as being changed, so they can be undone. Also made undo work for the new graph control.
  • Fixed the patch profiler (only for the profiled versions, not for the normal release version) to work properly for RateSmart modules. (Profiling adds about 8% performance overhead, so it is turned off for release versions.)

    And then removed a lot of needless profiling info from the report.
  • The 1 kHz fader for the third filter bank was wrongly named and hence that band was not working at all - fixed it.
  • The GVerb module was not properly locked against execution when it was being recreated, fixed that one and two or three other cases as well. Looks like overall stability got improved with that, in that undo/redo keeps working etc.
  • Error in MIDI running status processing. Only the first two bytes for messages based on running status would get interpreted. As for $90 $01 $02 $03 $04 only a note–on with velocity 2 for note 1 would be produced and the note 3 with velocity 4 note–on event would never get processed. Fixed that.
  • Sped up patch execution by about 5% trough removing some dynamic type checks from the inner execution loop. And by another 2% or so by skipping some profiling related code for the release version of the code. Sped up the dezipper code a bit too – but that's not really noticeable (as to be expected I guess as it works at control rate).
  • Added filter inversion for all filter bank modules. The idea is to invert every odd filter before the summation occurs and to not do that for the even filters. After doing some filter sweeps this does not seem to alter the filter response much though … it gets a little less bumpy (judged by listening), but then again it does not cost much. processor wise, so will leave it in anyway.
  • ClockGen - A clock generator module Made a clock generator module that acts like the Clavia ClkGen module. It can not sync to MIDI for now. The blue outputs have the internal phase accumulator values, these can for instance be used to implement your own swing functions by feeding them into a comparator.

    Added an input for external tempo control, this overrides the knob setting. This makes it possible to control the tempo with the Tapper module, which got a new BPM ClockGen mode added for that purpose.
  • Count - A counter indicator Made a count module, it counts upgoing signal edges on it's count input and it displays the total count. A frequency measurement tool would be handy as well (which would be a counter with automatic periodic reset).
  • FreqCount - A frequency counter indicator OK, made a frequency counter module as well, it counts upgoing signal edges on it's count input and it displays the total count over the measurement period recalculated to Hz. It is a bit of a primitive thing – like you have to wait for 10 s to get 0.1 Hz resolution. But seems handy to have still, and maybe will expand a bit on it at some later stage.
  • SeqRandVal - Y.A.R.S. Yet Another Random Sequencer! When quantize is on the internal values will be quantized according to the note fraction quantization value selected. When quantize is off the plain random values will be used as the internal value. The chain input is never quantized but just added to the current internal value after all other processing. The built in slew rate limiter can be applied either pre- or post-quantization, it does not act on the chain–in value.
  • Experimenting with speech synthesis a bit. Made a very simple speech module based on the Tiny Speech Synth. In the current setup it translates a sequence of phonemes to an internal wave file that can then be played just like the wave player does. tts experiment with tss

    Will need to rework this a bit to make it create sound on the fly. The idea is to make something like shown in the image (the 'song' module below). The module should flag text start and phoneme starts. With these signals sequencers can be driven to control the speech rate, the oscillator pitch and the amount of whisper.

    Getting there slowly … re-implemented the internal oscillator, so it can be properly tuned. Still struggling a bit with extreme duration modulations that are causing crackle – phoneme overlap is a bit of a PITA. And speech is not very intelligible, but not worse than say a human voice trough a G2 vocoder … maybe.

    I've changed the 'duration' control into 'speed', added oscillator wave form selection (saw or pulse, both anti–aliased). Added a filter configuration control as there was some odd pole or zero stuff going on in the normal mode which still may be interesting … but it can be turned on or off now. This works by inverting every odd filter's output before summation in the 'FI' mode.

    Song - TTS experiment with singing Changed the speed modulation a bit, but it is still not perfect – clicky at times. The PM I've added is quite useful though. Also I've added some more outputs, one that goes active on each 'silence' and another going active on each 'vowel'.

    I've made the default speed quite low (or actually the phonemes are quite long), to allow for very slow textures, but it can be sped up by a factor of 10 or so when using external speed modulation.
  • Vosim - A VOSIM thingie Made a VOSIM thingie. It is meant to be driven by an oscillator to set the rate and it can then control a single formant. Added 'Whisper' to make noisy tones, and AM to set the volume dynamically. The number of pulses can be modulated as well from one to the set number. The decay parameter controls the attenuation after each output squared sine pulse. The number of pulses and the decay factor determine the formant strength. The formant frequency is controlled with the formant parameters.
  • Graphical control Working on a new type of graphic control which can be used as a lookup element. For example in this new DataGraph module. The input would expect a [0,1], [-1,0] or [-1,1] signal and the output would then output the Y value for that X value also [0,1], [-1,0] or [-1,1]. It should be possible, when finished, to add points to and remove points from the graph. It would probably do linear interpolation to find Y values, but it's just an idea for now — working on it … currently it's an image.

    Ok, it is a working control element now that can be used on modules. Points can be added by double (or control) clicking into an empty area. Double or control clicking on a point allows the point to be moved. Removal of a point is just a move to somewhere out of the control. There is a minimum of two points in the control, one on the very left and one on the very right — these can only be moved up or down and can not be removed. There is a restriction on horizontal movements too, a point can not be moved to after or before an existing other point.

    When moving a point a crosshair cursor is shown, and in play mode a vertical bar cursor will be visible to indicate the current playback position. Not sure yet how that will work out at audio rate playback. Now to get a first working module with it … not so bad … good actually, the moving vertical bar works, now the rest.

    Graphical control The compiled synth now gets updates from the control on patch load and on point moves, just a little more work now in updating the synth data and making an interpolator for it.

    We have lift-off! After fixing some memory issues, of course, and some small tweaks … like decorating the dots a little and making it a transparent control :-)

    And now with splines too. Turns out to be not too bad for lower audio rates :-)
  • TypeFlip - A type flipper module Made a type flipper with slew control. A fixed input signal type can be set and for the output a left and a right type can be selected. When the select input is low the left output type will be applied to the left output and the right type to the right one. This is flipped when the select input goes high. The speed of type flipping is controlled with the slew parameter – when slew is set low the switch is immediate, when it is set to the maximum value the flip never actually happens. The selectable signal types are: 'normal', 'inverted', 'positive', 'positive-inverted', 'negative' and 'negative-inverted'.
  • Looper - A looper thingie Working on a looper thingie - it is a mess right now … well it basically works but it's clicky still. Added some mixing around the end loop to begin loop transition regardless of whether the playback pointer moves forwards or backwards. This helps somewhat … The amount of overlap can be set with the overlap control from zero to one.

    Changing the pointers to be relative to the in–pointer helps more. Sounds like it is click free now. Loop readout interpolation can be set to either linear or all pass mode. Both are having different artifacts, but linear seems to work better for long delay times and all better for short times. The maximum time can be set from 110 µs to 5 minutes. Duration and start controls are set as a fraction of the maximum time. Speed can be set from -4 to 4, negative speeds meaning the playback is backwards. For longer loop durations the modulation of start and duration are quite sensitive, decided to make the amount controls to work logarithmic.

Older release notes

License information

(C) COPYRIGHT 1999 … 2016 Blue Hell / Jan Punter

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation;

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

For all listed email addresses :
_dot. to be substituted by a dot '.'
2@t2 to be substituted by an at sign '@'

Blue Hell is a trade mark owned by

    Jan Punter

    Oogstplein 6

    7545 HP Enschede

    the Netherlands




Or alternatively send me a PM through the electro-music.com forum, my user name there is Blue Hell.

All rights attributed to Blue Hell are owned by Jan Punter.

For GNU license details see license.txt.


  • The icons for the 'gabe' look were made by .. gabe, also known as LfoHead on the electro-music forum. Thanks Gabe, they are great!
  • The Hrast modules and the file HrastUnit.pas are Copyright HrastProgrammer.
  • The included AudioIo unit is copyright John Mertus, and was modified a bit by me.
  • The included freeverb unit is copyright 'Thaddy de Koning / Jezar' and was modified by me to fit in better.
  • The included CpuUsage unit was downloaded from here.
  • The included OSCif unit was downloaded from here and modified for use in Wren.
  • The included portaudio material is Copyright (c) 1999-2006 Ross Bencina and Phil Burk. The DLL provided here was compiled from this source [you will have to obtain the ASIO SDK yourself through Steinerg, it is NOT included. The source contains some hints about how to do that] using Visual Studio 2013 Express. I had to make some minor changes to the configuration in order to get the code to compile. Also see http://www.portaudio.com/.
  • The included FFTW material (used for Fourier transforms in some modules) is Copyright © 2003, 2007-11 Matteo Frigo, Copyright © 2003, 2007-11 Massachusetts Institute of Technology. It was modified to be used in Wren.
  • The Talkie related code and the words.lpc file are Copyright 2011 Peter Knight This code is released under GPLv2 license, and it was modified to be used in Wren.
  • The included GVerb code came from here, the copyright message reads : Copyright (C) 1999 Juhana Sadeharju, published under a GNU General public license. I've translated the C code to Pascal.
  • The resonator code was modeled after Katjaas complex integrator that I found here.
  • The frequency shifter was copied from the Ladspa bode shifter that I found here.
  • ModTerragen uses some code that I found here.
  • For some of the envelope generators I've found inspiration here.
  • The Formant filter found it's origin here.
  • Some ideas that are in the Euclidean modules came from here and here.
  • The SVF module (not the Hrast SVF but the plain SVF) used some ideas found here and here.
  • The Pink Filter found it's origin here.
  • The Lorenz and Rössler attractor modules are based on code made by Thaddy de Koning (www.thaddy.com - (c) 2005) / Russell Borogove (www.tinygod.com - (c) 2004).
  • The WaveWiper was made after an idea published by PHOBoS, I got it from here.
  • Some wave wrapper modes were based on code and ideas found here.
  • The 'Poetry' generator was modeled after an idea by Johnathan Mackenzie from his Phd thesis 'Using Strange Attractors To Model Sound'.
  • The convolution code was built after the code found here.
  • The Rungler was built after an idea from Rob Hordijk, for more info look here.
  • Some of the speech synth ideas and some of it's code came from the Tiny Speech Synth by 'stan 1901'.
  • The BSpline code used in the DataMaker component was written by M. v. Engeland, I've made a couple of minor changes only to make it work in Delphi XE5. Please see the source code (BSplines.pas in the knobs2013 directory) for details.
  • For the speech stuff I've used C++ code from the Tiny Speech Synth written by Stepanov Andrey that I've translated to Delphi. See tss.pas and Speech.pas for details.
  • The TuneSmithy idea came from Robert Inventor.
  • The Moog filter type was found here. The following information was requested to be made available on reproduction of the code:

    Copyright (c) 2015, Dimitri Diakopoulos All rights reserved.

    Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

    * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

  • For the DaringFireball mark-down processor used in generating the help docs I've used code from Grahame Grieve. This in turn was a port of the TxtMrk mark-down implementation by René Jeschke. I've modified the code a bit for layout / readability reasons.
  • Andreas Trepte supplied the original picture of the wren, this was made into a logo by epwhorl and I modified it a bit later.

I may have forgotten some but I believe the list above to be fairly complete – please check the source code for more information. Thanks to all who so generously published their code for others to use and learn from