Feedback Paths Between Plugins

I’ve seen this question asked, but never answered.

I need to create a feedback path between two VST plugins.

The latest build of Cantabile 3 prevents me from making this type of connection. Is there a preference setting I have missed? I find it hard to believe that this is not possible, considering the mind-boggling flexibility of the program.


Feedback paths are problematic in Cantabile: they mess up the processing flow. Cantabile works in distinct buffers of audio data that gets processed sequentially by a chain of routes and plugins, then forwarded to audio out. A feedback cycle can’t be processed within such a processing run - you’d need to go back in the calculation to a previous (already concluded) calculation over and over and never finish.

That’s why Cantabile’s routing doesn’t allow any feedback loops or cycles.

To get around that, you need to “break out of the buffer processing”: you can send the output from a plugin to a loopback port and then use the input from that port for your feedback loop. Using a loopback port essentially puts that output into the next processing buffer, thus allowing correct sequential processing flow.

  • create a virtual audio input port called “feedback”, not attached to any physical input
  • send the feedback output to audio port “Loopback: feedback”
  • use the “feedback” input port for wherever you need this fed-back signal

Note: there is a delay of the length of one audio bufffer inherent to using Loopback ports - that’s the price you need to pay. Essentially, Cantabile “parks” one audio buffer of that specific output to be processed as input for the next cycle.

Hope that helps!



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That totally helps. Thanks for the explanation, and the suggestion.

I’ve also asked for similar. Cantabile prevents me from creating feedback loops, but it’s a pain, as it stops me from bringing send FX (and my looper) back into my mixer Rack.

Really hoping for a shift in this!