Roland style feedback oscillator


I used to own a (in)famous Roland synth with supersaws back in the days. It also had a feedback oscillator. I miss the sound of this, although not regretting selling that MP3-sounding piece of **** hardware… :smiley:
I can replicate the Rolands supersaw easily in Vital, but have not found a way to recreate the feedback oscillator.

Is there anyone who has a feedback oscillator wavetable, or is this a feature that can be built in?

Best regards,


Google tells me the “feedback oscillator” is basically just a saw with a keytracked comb filter that self-resonates.

So I made a saw oscillator and a keytracked comb filter that self-resonates. I have a “feedback” macro that brings in the comb filter… I also have a “harmonics” macro, which pitch-shifts the comb filter across an octave. In an attempt to capture some of the sound I also used a hard-sync on the saw oscillator as feedback is brought in (my ears told me so, no good reason otherwise).

It’s certainly not a faithful recreation of the JP-8000 but the result is interesting and it produces a lot of similar sounds, to my ear. In many ways you get more “faithful” feedback results doing the converse of what I did: dragging the pitch of the source saw across an octave while leaving the comb in place, instead of moving the comb… but this won’t interpolate correctly if you fade the feedback in and out (because at 0% feedback you’ll just have a pitch-shifted saw). So depending on how you want to use it, use either the Harm or Harm Alt knob; the former will probably be a better approximation if you want to set a harmonic level and manipulate the feedback, the latter a better approximation if you want feedback at maximum and just want to scream the harmonic slider until it sounds like a guitar placed in front of a very loud amp.

Compressor to tame levels, Chorus because unison doesn’t work well (since the comb filter is not unison’d, it seems like filter key tracking doesn’t respect unison detune), downsample because JP-8000

Feedbacker.vital (170.9 KB)


gr8 preset good starting point like the way this going ! thanx

Awesome, thanks!

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