mx.synths: like or mr.radar, but for instrument synths. (companion to mx.samples).


  • norns
  • midi keyboard


  • K2/K3 changes instrument
  • E1 controls mod1
  • E2 controls mod2
  • E3 controls mod3
  • K1+any E controls mod4

mx.synths is a collection of eclectic polyphonic synths.

each synth has a specific style that can be tweakable via “mod” parameters. their are four mod parameters and they are synth-specific (though usually mods 2 and 3 are frequency and resonance respectively and usually mod 4 is detuning). all other parameters - found in the MX.SYNTHS PSET menu - are shared for each synth. most the parameters are evident (delay send, adsr, etc.). one special parameter is called “sub”. sub is synth specific (and not implemented in every synth) which activates some sound with low-note priority. many of the parameters have lfos.

since all synths share the parameters menu, you should save your settings if you find a patch you like (PSET > SAVE), so it is easier to come back to.

the synths

piano: this is an ‘acoustic piano’-like synth from @zebra’s DreadMoon engine. it is essentialy noise being filtered through a comb filter. the mod parameters can make it sound more like a drum than a piano sometimes. mods:

  1. decay
  2. noise freq
  3. resonance
  4. detuning

epiano: this is an electric piano based on FM rhodes type sounds. it is taken with minimal adjustments from snappizz’s FM Rhodes SynthDef. mods:

  1. lfo depth
  2. mix
  3. modulator index
  4. lfo speed

casio: this is an emulation of the phase distortion synthesis from the 1984 Casio CZ-101. I implemented it purely based on their patent and has all sorts of weird artifacts. mods:

  1. artfiacts
  2. phasing
  3. resonance
  4. detuning

malone: malone comes from designing an organ sound for a drone. it is a heavily modified version of Svdk Vedeka’s port of Coloscope’s pure-data organ. mods:

  1. detuning speed
  2. filter
  3. resonance
  4. detuning

toshiya: this is a another from sound designing for making drones. I wrote about it here. it has a klank sound that can be modulated. mods:

  1. pitch spread
  2. klank volume
  3. filter oscillator
  4. detuning

synthy: this is the basis of a couple of synths - starlids and synthy, this is yet another iteration. mods:

  1. stereo spread
  2. filter spread
  3. resonance
  4. detuning

PolyPerc: this is the classic PolyPerc engine from @tehn, with some adjustments. mods:

  1. pulse width
  2. filter
  3. resonance
  4. detuning


icarus: this a slight modification of the icarus script, a variable-sawtooth oscillator with variable feedback. mods:

  1. feedback
  2. delay time
  3. PWM width
  4. detuning

mdapiano: simply based off the SuperCollider MdaPiano. mods:

  1. stereoness
  2. vibrato rate
  3. vibrato depth
  4. detuning

kalimba:based off the p.dupuiskalimba, which is a fork from @nathan’s kalimba… mods:

  1. stereoness
  2. vibrato rate
  3. vibrato depth
  4. click mix

usage as library

mx.synths can be included in other libraries. its probably easiest to change the engine and import the menu library:"MxSynths"
local mxsynths_=include("mx.synths/lib/mx.synths")

now you can edit the current sound by directly editing the parameters, as all the parameters will update the engine. to then play a note you can use


the <duration> is the number of seconds to automatically release. it effectively lets you choose whether it will play as a “one-shot” synth. if you want it to be “one-shot” then set the duration to the duration you want and it will be released after. if you want to instead use it with note off signals, then you should set <duration> to a large number (like 600 seconds). then you can tell it when you want to do the release by sending a subsequent command:


there is a helper function to do one-shot playback, you can simply do mxsynths:play({...}) with all the parameters you want, e.g.:



there are a couple limitations that may become obvious when you spend time with mx.synths.

first - while you can play multiple synth voices simultaneously, the way I wrote the engine is such that only all synth voices will voice-steal from each other if they are playing the same note. (also currently there isn’t a engine command to send all the parameters, rather the parameters are gathered from the PSET menu, but that can be added soon).

second - polyphony is not limited in the engine, but it will be limited by the norns cpu. probably 8-10 polyphony is the max for most synths. setting a quick release if you can will help with this. the synths could also be better optimized I’m sure.

making your own synth

any and all contributions are welcome and accepted.

making your own synth is a simple process. there are three basic steps.

  1. make your SynthDef. start with a basic SynthDef like this:
    arg out=0,hz=220,amp=1.0,gate=1,sub=0,portamento=1,
    var snd,env,pw;;;;;,portamento).cpsmidi;,decay,sustain,release),([0,0,1],[duration,0]))),doneAction:2);

    // <yoursynth>
    // (optional but recommended) map the mods to something/
    // mods always sent as [-1,1] so they need to be mapped:,-1,1,0.2,0.8);

    // make some sound
    snd =,width:pw);
    // </yoursynth>

    snd =,,0.1));,snd*env*amp/8);

once you finish, you can paste it into the, like around here.

  1. add “your synth” to the registry. edit l.synths in the lib/mx.synths.lua script to include the name of your synth. make sure it matches exactly what you named your SynthDef is step #1.

  2. (optional) add some graphics for your synth. simply write a function that draws something to the screen and update redraw() in mx.synths.lua to run your function when it is selected.


this script wouldn’t exist without @zebra, who gave me lots of guidance in SuperCollider in general and also the “piano” is from their DreadMoon engine. thanks also to @tehn, a version of PolyPerc is in this engine. and thanks to @snappiz which the “epiano” is adapted.


  • [ ] add monophonic/portamento
  • [ ] add BPeakEQ to the fx stage
  • [ ] add tremelo to the fx stage
  • [ ] add noise version of each synth (noise level, adsr)
  • [ ] integrate into plonky
  • [ ] integrate into o-o-o


install with


ON FIRE OMG – angel, saint, mad scientist.


this is so good! :exploding_head: :exploding_head: :exploding_head:


Beautiful! (!!!)


Lol, I’m legit halfway between shocked at your output and in a way, spoiled by what you do. At this point, there’s definitely a before and after @infinitedigits in my mental Norns timeline. Bravo


Sound design on these engines is just impeccable IMO :clap: and I love how the default for LFOs are in the 20-40 second range :slight_smile: An absolute joy to dive into so far.

And of course, thanks so much for making and sharing this! Literally implements 2-3 separate script ideas I’ve had all in one go!


Infinitedigits you’re a generous wizard. These sound absolutely awesome, and what’s on screen is stunning as well. Really really beautiful. I’m stoked to use gridkey mod and make some layers with mx. sounds tonight on the monome grid :star_struck:


thank you for this early morning fun time! what should we try to resolve stuck notes? i been experiencing a couple here and there amongst the different instruments and adjusting stuff like release or sustain etc doesnt make em go away lol



what I tried the other day with stuck notes on Molly The Polly was to play the same note again. maybe that will work for you?

wow, Zack, this is super rad! I don’t know whether I should be surprised that 4-5 note polyphony is the suggested max. how hard would it be to help raise this limit?


man i cant remember which note it was and i dont have one of them “golden ears”, maybe MIDI monitor will tell me which note it is. Or i could just spray some PAM on my keyboard? jk


oh I did a lot of keyboard smashing to clear those notes for SURE haha


thanks everyone! I hope the synths carry you to new places. if you want to add your own and it seems hard, feel free to hmu and I can guide you. it is pretty easy.

lol well I already changed this as I was overly pessimistic… the “4-5” was based off the most cpu hungry one (“malone”) but now I’ve changed Pulse to PulseDPW so that one is better now. I’ve been playing them with a sustain pedal and I haven’t been getting any cpu crackles even with >9 notes down on all of the synths. but it really depends on how you play I think and how your release tail is set.

are you able to get notes stuck reproducibly? are you using a sustain pedal? (I very very recently fixed a bug in the sustain pedal, like 10 minutes ago lol whoops, but otherwise I haven’t been getting stuck notes :thinking: ).

feel free to fork and add your ideas! its easy. itd be great to have community contributed things in mx.synths. its pretty modular - you can simply add your synthdef and then add any graphics you want (or use the default graphics which are just four lines). if there any questions I’m happy to help.


Thank you (again) @infinitedigits ! Just in time for weekend explorations


seems like its only happening when I get too crazy. imma check on the sustain setting though and see what’s up with it. thanks again!


the graphics look simply stunning and i can’t wait to dig into this!


A work of art.

Beautiful, responsive and informative graphics.

Sweet, sweet set of sounds.

Turned on all the LFOs and held down some chords, entered paradise.


This is amazing and inspiring. Thank you.

1 Like

very excited for this, looks amazing!

1 Like

@infinitedigits jaw dropping, yet again. Geez your Home Run record is unparalleled. Thank You!

1 Like

I cannot wait to get home. This is awesome. :slight_smile:

1 Like