FM 2 Op Drum

FM 2 Op Drum V1.2.audulus (35.7 KB)

FM 2 Op Drum

This module was made as a one-off for a song I was working on, but has stuck around and proven to be very handy. The time is right to give it a few tweaks and post it for general consumption.

I have added feedback and removed ring modulation for the simple reason that ring mod made the sound quieter and feedback brings the noise!

FM 2 Op Drum IDM Demo.audulus (563.7 KB)


Input Signal Range Notes
1/oct -5 to 5 This allows for pitched drum sequences or you can use this as a gritty bassline synth
trig 0-1 Trig input does not respond to gate length.


Knob Function Notes
Screen Shot 2020-03-07 at 2.55.20 PM124x162 Modulator Frequency Set the frequency of modulating operator.
Screen Shot 2020-03-07 at 2.58.09 PM125x156 Modulator envelope decay length The shorter the pluckier.
Screen Shot 2020-03-07 at 2.58.22 PM141x156 Modulator waveform Saw and square add a little aliasing but it sound percussive.
Screen Shot 2020-03-07 at 2.58.27 PM131x163 Modulator envelope decay curve Log will prolong the modulation effect and exponential will make it more plucky.
Screen Shot 2020-03-07 at 3.04.57 PM125x155 FM intensity How much FM do you want?
Screen Shot 2020-03-07 at 3.05.05 PM120x155 Feedback Final output is fed back into the FM input of both operators as this parameter is increased.
Screen Shot 2020-03-07 at 3.05.12 PM119x152 Low Pass Gate Envelope Decay The output is filtered to remove upper harmonics from long decays.
Screen Shot 2020-03-07 at 3.05.28 PM131x163 Low Pass Gate Envelope Curve The pluckiness of the sound increases as this parameter is raised.
Screen Shot 2020-03-07 at 3.11.04 PM125x159 Carrier Frequency Set the base frequency of the carrier oscillator.
Screen Shot 2020-03-07 at 3.11.11 PM118x156 Carrier Pitch Envelope Decay Time Name says it all.
Screen Shot 2020-03-07 at 3.11.16 PM130x157 Carrier Pitch Envelope Intensity and Polarity The pitch envelope can be inverter for some nice disco tom action.
Screen Shot 2020-03-07 at 3.11.19 PM120x156 Carrier Pitch Envelope Curve This was included for fine tuning the inflection of the pitch envelope.


Yes! Sounds great! :+1:

1 Like

At some point it would be nice to have a gate input to change between waveforms (the Karplus Strong VCO from the Reface Library could use this too); or even a dual oscillator version with separate enveloping. I have made patches with two these to get a fatter kick drum. All told, this is my most used module and I ended up selling my Dinky’s Taiko because of it. Thanks so much for building it.

1 Like

Super ! thanks a lot !

1 Like