I was trying to do feedback by taking an output of a filter, putting it into a splitter and then taking one output and running it into a mixer that was in front of the filter. Nothing seemed to happen, no matter what I did. What am I doing wrong?


things to take into consideration:

  • each cable delays the signal 1 sample.
  • no noise is introduced by default in any VCV modules.

in the physical world, we can make mixer feedback, because there is noise to amplify, and slew rate limiting / filtering in the amplifiers (etc, I’m not really an expert.)

I’m sure some of the gurus in here can explain it much better.

If you want to play with feedback, one module worth looking into could be

link to the fine docs: GitHub - philippesalembier/SckitamVCV: Plugin for VCV Rack

Here’s a test setup:

feedback_test.vcvs (15.2 KB)

Right, but maybe I didn’t explain it well. I’m taking a wavetable oscillator, feeding it into a mixer. From the mixer, it goes into a filter and then a splitter, and one half goes to the output, the other goes back into the mixer, so it theoretically should give me feedback, no?

Sounds like it should give a feedback loop - perhaps it just hits the upper or lower voltage and stays there ?

You could try checking with a “scope” - and post a screenshot.

Some feedback can happen for sure:

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I figured it out. It was the mixer I was using. Not sure why, but it blocked feedback. I was using the Befaco four channel mixer, and that was the culprit. When I switched to the VCV VCA mix module, it works as planned.

My next question is… what is something like the Prophet 12 doing when it says “tuned feedback?” In my head I imagine it to be some sort of filter with resonance in the path? Must experiment!

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from the Prophet 12 Operation Manual p 23:

There’s a tune knob on the delay I mentioned earlier.

In the right-click menu, you can set the mode.

Here’s his demo patch Karplus_Strong.vcv (2.5 KB) saved in rack v2