Caustic Song file (optional):
Using the Machine Input for the Modular in Caustic 3.1 I made an effect that works kind of like a tape echo.
Once you open the file you find 2 Modular synths on position  and .  is the echo effect,  is the sound feed. The effect works kind of as a sidechain effect. In order to make it work flip the effect and turn the "In 2" knob of the top mixer to the right. Be careful, the feedback is not controlled and could possibly destroy your speakers if you are not careful. You can adjust the sensitivity of "In 2" with the "Output" knob of the top mixer. The Release of the envelope is the time the echo has to get to minimum cutoff frequency until retriggered (in the example by note on event). You can play around with different delay times but I found these settings worked best for me (the 2 rate knobs on the front). Playing around with the filters won't do much, and increasing the resonance could have cool effects but makes the signal fizzle out quickly (just the way the filters are programmed). Feel free to use this effect. Just make sure the notes are played from the effect sequencer or else the filter envelope won't trigger and the effect sounds a bit shallow.