Boss DS-1 Gating the octave synth mod(s)

[rbxqb]

I'm finishing off a couple of projects I worked on a couple years ago, including my Boss DS-1, which has a combination of the Keeley Seeing Eye bend, and three switches that short various points on the circuit to create adjustable drones of feedback when sweeping the distortion control.

The most interesting sounds occur when the distortion knob is dimed, but it would be great to gate the input signal to avoid the constant feedback occurring when the guitar is not being played - i.e. make the input sensitivity a bit more dynamic when these mods are engaged. I have played around with using a 1N4004 diode between the shorts, which does seem to gate it a bit but also changes the character of the sound drastically.

The shorts are between C4 and three separate points on the circuit: C9, C10 and R16. If there is a way to gate the signal when any of these three shorts are activated, that would make the mods a lot more dynamic! I am attaching an image of the PCB with the points mapped (red = C4, blue = C9, yellow = C10, green = R16).

[garcho]

WELCOME TO THE FORUM!

Gates are complicated. They're basically envelope detectors and VCAs, entire circuits onto themselves, not single components. You can't just "mod in" a gate. The only single-component way to do it is as you mentioned, using diodes' forward voltage as a gate. They don't gate in a "musical" way, they sound like something is "broken". For experimental music, where often part of the artistry is reacting to unpredictable elements, it might work.

Look at different types of diodes and their forward voltage ratings, the higher the V_F, the higher the gate threshold.

You can make a q&d simple gate with a transistor and a few passive components but you'll need a daughter board.

You can always just buy a cheapo noise gate pedal and throw it in your chain. Easy to find something in a 1590a for ~30USD.