Since the Shapeshifter has a digital delay with the delay time exposed for control via the “Pitch 2” input, I thought that I’d try a Karplus-Strong patch. As there was no appropriate un-pitched internal noise, I patched external noise into the “Mod A” input, and used that in place of oscillator 1 (Mod A Combo 1 setting). I using the percussion mode with an external trigger applied at the “Sync” input to avoid the need for an external envelope and VCA. Applying pitch CV from a keyboard to the “Pitch 2” input with delay feedback settings between 50 and 70 gave some reasonable results with unchanging pitches, but the slew effect resulting from changing the pitch CV made it unusable for a controlled melody.
I imagine that this is due to the slew-rate limiter applied to the period of oscillator 2 which is referred to in the manual. Whatever the cause, I wonder if it might be possible to introduce a mode that would remove this slew effect and open up the possibilities for Karplus-Strong patches. It might also be handy to have un-pitched noise available internally (with different colours ideally).
Many thanks to Intellijel for creating such an excellent module.
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