3-way toggle switch in Dirtbaby delay?

[dmitrogen47]

Hi everyone!
In my Dirtbaby I have a 2-way toggle switch for Vibrato/Chorus. If I want to have no repeat modulation, I turn Rate and Depth all the way down.
What if I were to install a 3-way (center off) switch there, would it work? Would the center position give me no repeat modulation without negative effects on the way the pedal sounds?
Thanks in advance!

[r080]

I was thinking about the same question. I ordered the dirtbaby this week, but have not built it. If I am reading this right, IC3A is a schmitt trigger, and IC3B is set up as an integrator. I think switching between the capacitors just gives different levels of integration on the pulse, so leaving it open would essentially make your modulation a big square wave, not what you are looking for.

I was considering getting a DPDT center off toggle, wiring one side to switch the caps, and one side so the center position opened the positive feedback between R34 and IC3 pin 3. I honestly don't know if this would work. Another option would be shorting the depth pot wiper to ground. I didn't take the time to figure out how to make this work.

[r080]

Another PT2399 design, the Echo Base has pretty much the same LFO. That design has a switch to short out the feedback cap on I3B to turn off the modulation.

[r080]

I think I got it. With a center off SPDT, connect the middle lug to pin 3 of the depth knob as normal, connect the 2.2u capacitor as normal. Connect the 0.47u capacitor from the middle lug of the switch to pin 6 on IC3. In the spot where the 0.47u is supposed to go, put a jumper. You would then have 3 positions: shorted/defeated, 0.47u, and 2.67u.