Bypass when on, mute when off

MacGuffin_

Member
Honestly, not even sure how I got here.

Building abyss, when I turn on the switch (LED on) I get a clean signal. When I turn it off, I get nothing. Can I get a sanity check with my wiring? I am using this 3pdt board [Link].

I already tried removing the modded LED, no luck. Yellow is jack in, blue jack out. red is board in below and black board out. red (+), black (-) up top, and green is always ground.


PXL_20230529_021517228.jpg
 
Tried jumping directly between the tips when bypassed with 0 change. I am no expert, but I assumed that it would "connect" it as if it were bypassed that way...
No luck with reflowing the board either.
 
Honestly, not even sure how I got here.

Building abyss, when I turn on the switch (LED on) I get a clean signal. When I turn it off, I get nothing. Can I get a sanity check with my wiring? I am using this 3pdt board [Link].

I already tried removing the modded LED, no luck. Yellow is jack in, blue jack out. red is board in below and black board out. red (+), black (-) up top, and green is always ground.


View attachment 49426
What is that white wire doing connected to your Ldr?

No audio when effect is activated, audio in bypass.

After confirming my wiring is correct which I ca’t really do because I have no idea where what goes on that switch daughter board. I’d check my voltages of my ic’s. Is your led lighting up and and being affected by the rate knob. Some will also say you need to test this in the dark, I did not test this circuit in the dark and it worked fine in the light when I built it. But it probably wouldn’t hurt either. But again first thing I would do is confirm my voltages on the tl074.
 
What is that white wire doing connected to your Ldr?

No audio when effect is activated, audio in bypass.

After confirming my wiring is correct which I ca’t really do because I have no idea where what goes on that switch daughter board. I’d check my voltages of my ic’s. Is your led lighting up and and being affected by the rate knob. Some will also say you need to test this in the dark, I did not test this circuit in the dark and it worked fine in the light when I built it. But it probably wouldn’t hurt either. But again first thing I would do is confirm my voltages on the tl074.
White wire to LDR is a mod to the LED (lets the player know what rate/intensity the pedal is currently at by mimicking the LFO LED). It shouldn't interrupt anything being in parallel from my basic knowledge of circuits.

LED (both footswitch and the one that oscillates) light up fine and are effected by rate. I get no sound whatsoever, so there are probably other issues that I haven't discovered yet
 
D

Done, the entire circuit from jack in to jack out has continuity (except through C1, which it shouldn't have). Still no sound :/
When troubleshooting it’s best to reset all mods to stock- even the bypass LED / LDR mod.

Try disconnecting your white wire from the LDR and report back!
 
Saw a reply that doesn't appear here for some reason: The resistor on the 3PDT board goes to the anode of a 3PDT LED then to ground after the LED. Didn't want to connect it to the right CLR pad because IDK what voltage that thing is getting and didn't want to dirty the +9v rail
 
Saw a reply that doesn't appear here for some reason: The resistor on the 3PDT board goes to the anode of a 3PDT LED then to ground
I deleted it because I wanted to study the GPCB board to make sure my comments were right. I see why you did it, but I’m wondering whether that’s not messing with your input signal. (The fact that board requires +9v and ground means it’s not immediately compatible with PedalPCB boards which is something it appears you recognized.)

Try disconnecting the ground wire from the daughterboard and see what happens… beside your LED becoming nonfunctional, of course.

ps. Anode = positive leg on an LED, so i wouldn’t expect it to work properly if you’ve wired it that way.
 
I deleted it because I wanted to study the GPCB board to make sure my comments were right. I see why you did it, but I’m wondering whether that’s not messing with your input signal. (The fact that board requires +9v and ground means it’s not immediately compatible with PedalPCB boards which is something it appears you recognized.)

Try disconnecting the ground wire from the daughterboard and see what happens… beside your LED becoming nonfunctional, of course.

ps. Anode = positive leg on an LED, so i wouldn’t expect it to work properly if you’ve wired it that way.
No dice, also tried shorting the board ground to the middle switch lug with nothing there either.

Resistor on anode has worked fine for me so far, it's how the board is wired by default anyway.

The 9v rail doesn't seem to actually attatch to anything if you don't give it supply, so I was assuming that it was just a dead rail.
 
Also have you tried running the circuit through a test box. It’s a really good idea to try the circuit as basically as possible before adding a your switch etc just to see if the circuit works before you add all these other variables.
 
Also have you tried running the circuit through a test box. It’s a really good idea to try the circuit as basically as possible before adding a your switch etc just to see if the circuit works before you add all these other variables.
I haven't built a test box yet, it's part of the next lot I do but don't have the money for more components atm
 
Take a dmm set it to dc voltage and read the voltage at each pin of the ic. Place black probe on ground and then touch the red probe to each of the 14 pins right down each voltage and list them here.
074:
4.5 [ ] 4.5
4.5 [ ] 4.5
4.5 [ ] 4.5
9.0 [ ] 0.0
4.5 [ ] 4.5
4.5 [ ] 4.5
4.5 [ ] 4.5

072:
4.5 [ ] 9.0
4.5 [ ] 4.5
4.0 [ ] 4.5
0.0 [ ] 4.5
 
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