Relay Bypass For Dual Effects

[dfx_pedalpcbs]

Pedal dudes

How do I go about doing a true bypass soft switching system for dual effects like the King of Tone. Do I need 2 relays and 2 micro-controllers?

Thanks

[digi2t]

I still have a Sputnik III open on the bench, but it's been a while since I looked at it. If memory serves me, it's a single micro controlling two relays, one for the bypass and the other for the drift function.

I'll take another look tonight.

[electrosonic]

one uC and two relays seems the easiest. If you used a non latching relay you could use one pin per relay, maybe to control a transistor to switch the relay on / off - if you're clever you can use the same pins to turn leds on and off to show the effect status. Footswitches would take two more pins for a total of four pins, so a 8 legged uC would work (Attiny85 or Attiny13A in the arduino environment would work)

Andrew.

[digi2t]

Didn't have to wait to get home. Here you go...



I believe that the transistor to the left of the uC and cap is most probably the jfet used for switching the drift circuit.

[dfx_pedalpcbs]

Didn't have to wait to get home. Here you go...



I believe that the transistor to the left of the uC and cap is most probably the jfet used for switching the drift circuit.

nice 1 mate, you have a schematic of the 2 switcher system, does it switch leds aswell so you know which side is on

[digi2t]

It switches two LED's, under one bezel. The two LED's on give you a mixed color of the two when both are on.

I didn't bother tracing it as is because I would use two 12F675's with the Coda code. It would only take up a bit more room than the current single Attiny. Besides, I have no programming abilities whatsoever, so I have to use off the shelf solutions.

To be honest, in the Sputnik case, I have no idea why Spaceman went to all the trouble of the uC setup. The first two Sputniks didn't exhibit any switch pop, so I suppose the only advantage is the ability to select between latching or momentary operation.