What is the 'Comb' waveform?

Hi everyone,

On the Digitakt (and I believe on the Model:Samples as well) there is a factory single-cycle waveform called ‘Comb,’ which has a really unique timbre. I want to be able to synthesize this type of waveform on software, but I can find zero information about it online whatsoever. I can only assume it involves a comb filter, but I don’t know where to begin after that.

Does anybody know how this type of waveform is synthesized? Does it involve a comb filter, and if so, how can that be used to generate this single-cycle waveform? Thank you!


Scientifically I can’t give you a good answer and I don’t know about the specifics of that SSWF…

However, you’d probably be right to assume it was created with that technique. Comb filtering is the result of copies of the same audio phasing. One of the most fun ways to do this is with short (1-50ms) delays, and you can see that changing the MS value changes the perceived pitch of the “combing”.

However, the simplest way you could do this is just take an audio channel on track “X” in your daw, copy the same audio to track “Y”, and offset these two audio tracks by a ms value. This is the same trick as the delay thing I mentioned above, just with no feedback and not easily modulatable.

You’ll notice that by increasing the feedback using a short delay, or taking a comb filter (such as the one built into Serum fx which is really good, theres some good ones in VCV rack as well) and increasing its resonance, you’ll get really cool metallic timbres, and this is one of the most timeless sound design tricks IMO.

It is also the root function of Karplus strong synthesis, which uses a simple audio impulse/trigger, and a short, resonating delay.

The longer you play with short delays, comb filters, phasers, and flangers, the more you will realize how many ways there are to achieve phasey, metallic sounds, which is pretty awesome. Lots to explore and play around with.


This is all very helpful, thanks so much for the response!

Hmm, that one was probably made with a Make Noise 0 coast if it’s one of the weirder shapes.

I didn’t use any comb filters for any of the single cycles.


Screen Shot 2022-05-12 at 12.48.58 AM

It looks like this, if that’s helpful at all.


I never noticed that waveform, so I wanted to thank you for bringing it to my attention. I really like its timbre. I use the Digitakt mostly for drums and often forget about its ability to play single cycles waveforms.

For what it’s worth, the waveform kinda looks like a comb :wink:

It sounds like this wasn’t a comb filter, but this thread still inspired me to experiment with comb-filtering some sounds to then load in the Digitakt where single cycles can be selected for looping. So far I’ve sampled some stuff directly from the OT with its comb filter with modulation and had interesting results. There are also software comb filters I like that I might try next, like the stock comb filter in Renoise and a couple others. Maybe I’ll put a kit of single cycles together and upload it somewhere.


Oh fantastic, I’m excited to see if you come up with anything.