[sdiy] Monosynth features poll

[David G. Dixon]

Ian, that's really cool and well thought out.  There are lot of patching
ideas in there, and also perhaps clever ways to "normalize" (pre-patch with
switchable jacks) a modular system.

This begs the question (at least for me), why not embed dedicated LFOs in
other modules such as VCFs?  As someone pointed out, one TL072 and a few
passive components does the trick.  One could develop a tiny little "utility
LFO" board for this purpose, perhaps right on the rate pot itself, as a
"chiclet" type thing...


> the first idea I had was something like this (a diagram would be better,
> but...):
> 
> two VCOs (Ramp/Rect w/ PWM) - VCO 1 CV is controlled by the keyboard, VCO
> 2 CV can be switched between the keyboard and an 8-step sequencer. An EN
> Timbre Modulator is switchable between the two VCO outputs and is
> controlled by a saw/tri/ramp LFO. Outputs from both VCOs, the Timbre
> modulator, and a Noise source (I'm particularly fond of the grainy noise
> from Ray Wilson's Noise Cornucopia) all go to the Lowpass/Bandpass 12
> dB/Oct VCF. Cutoff frequency is controlled by an ADSR that's
> gated/triggered by either the keyboard or the sequencer. The resonance is
> controlled by another LFO. The Bandpass and Lowpass outputs are mixed into
> the VCA. Most likely a Log/Lin VCA, the gain is ADSR controlled again
> gated/Triggered by either the sequencer or the keyboard. The sequencer
> would have the Thomas Henry controller clock with external override from
> the Drum Cookbook allowing the sequencer to be clocked by either the
> internal clock or the keyboard trigger out.