Caustic Song file (optional):
So you send a burst of noise through a delay-filter feedback loop, with the delay time determining the note played, and bam, you've got a plucked string, yeah?
So a normal delay is probably going to be too long to be useful (although the first person to make a melody by using a normal delay module and modulating the *tempo* of the song gets a cookie,) but one of the quirks of a digital modular synthesizer is that it takes time to process all the modules.
The modules are processed left to right, top to bottom, so the only delay we can get is by placing the next module in the signal flow to the left of the previous module. Lucky for us that's a somewhat usable almost a quarter tone below an F.
All we can do is change the number of delays the signal goes through before it reaches the filter, so if that low C# sounds a little out of tune, that's because we're making notes on the SUBharmonic series, isn't that some shit? en.m.wikipedia.org/wiki/Undertone_series
The actual modules aren't anything special. A K35 LPF because it's the best at incremental filtering. The delaying modules can be anything, here they're just mixers. The faders on the top right mixer correspond to taps in the signal, the further right, the fewer delays it goes through.
This is a temperemental beast, try not to let it feedback too hard, or at least take off your headphones. You can actually use the decay env itself as the initial exciter, but I think it sounds better with the noise.
P.S. As a bonus, a tuned bandpass filter on some white noise, because I didn't spend two hours tuning it for nothing.