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Silent Momentary switch with Pot

Started by jghfslk, December 02, 2017, 02:02:06 AM

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Boba7

You should have a look at the Triton delay by culturejam. I think it does exactly what you want.

WormBoy

That is indeed the simplest option; no optocoupler needed. I found the link to the build doc and schematic here: http://www.madbeanpedals.com/forum/index.php?topic=22053.msg217073#msg217073. The resistor plus cap should prevent any switching noise. There is a video to check out if this is what you're looking for: https://www.youtube.com/watch?v=cpLMAIetGZc.

jghfslk

The Triton delays looks really cool and gets close to want for but I don't think it can do exactly what I'm going for.  With the triton, it seams as though the time gradually shifts from one setting to the next.  I'm hoping for an instant change for the time control.  It would be like a square wave modulation that has a very wide shift but you can control exactly when the shift occurs and also the amount it shifts.

Would it be possible to use an led/ldr combo to control both of the delay times and shift between them with user control?  I don't get why when using a switch to shift the delay times the pop happens, but when using an led/ldr modulation board with a square wave setting the time can shift widely without the rumble noise.

WormBoy

In the Triton design, there is a pot that deals with the speed of the transition. Plus, you might be able to use a smaller cap and still avoid noise. My guess is that the noise creeps in with a switch as there will be a tiny moment when resistance is infinite (in between the two positions). If you would use an LDR with a square wave LFO, the resistance will never be infinite, and the shift will not be instant as the LED and LDR will have a non-zero response time.

jghfslk

I added a capacitor from pin 6 of the pt2399 to ground similar to the Triton delay and I am now satisfied with it!  I used a switch to have the option for a long change and a short change.

WormBoy

Great! I love simple solutions  ;D. This trick goes into my archive; bound to be useful for future builds.