SOLVED Tyrian only has sound in bypass

onemhz

New member
I've been reading troubleshooting guides and continuity testing for hours now. This is only my second ever pedal build and I still have a lot to learn about how the circuits work, how to debug and such - to be honest, many of the debugging guides go just a bit over my head. The problem I have is that I only get sound in bypass. No audio comes out or LED comes on when plugged into power, input/output connected and switched to active.

I've checked continuity on all combinations of lugs for the foot switch to make sure I didn't burn out the internals or accidentally connect two that shouldn't be. I've probed all of the components that connect to ground. I've traced DC voltages all over the circuit - from the lugs on the DC jack to everything that looks like it's connected to the power circuit or VREF in the diagram. And I've even probed for AC voltage and I can at least see some response around the circuit and all the way to the output jack lugs when I strum a guitar with it all on and active - though I haven't seen a troubleshooting guide so I don't know if that's just chasing a red herring.

I've got a pair of Switchcraft 112AX stereo jacks but only the tip and sleeve are wired - tips are left side, sleeve is right, ring is center in the picture. I alligator clipped in some basic metal TRS jacks just in case I bought some crazy Switchcraft configuration that is wrong for this kind of build - but got the same result - sounds comes through fine in bypass but nothing in active. I think I wired the 3PDT like the diagram. I've got dust covers on all of the potentiometers. I've checked and re-checked that I put the LEDs in the right way around (longer lead/positive end on the "A" side and shorter/negative on the "K"). I did put a 5mm blue LED instead of red for the active circuit indicator, but otherwise I think I got everything right per the build guide. Also, forgive the extra hole - drilled for the DC jack, but realized too late that there was a bit of a space issue with the pot there.

I can't tell if I'm probing the wrong things or checking the polarity wrong. But I'd really love some ideas of what else I could've done wrong with the build or my diagnostics. Again, please treat me like an absolute beginner. Let's just say my first build didn't so much... work either.

PS: I'm dying to get my hands on the Auditorium Test Platform board. I feel like it could really help figure things out.

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Ok. Process of Elimination!
Just wrap some tape on one end of leads.
plug taped end of Lead into Guitar & other end to Amp, Result?
Reverse same lead & plug into Guitar & other end to Amp, Result?

Do the same with other Lead & report back findings!
 
I’m not sure I understand what I’m testing for. Am I taping the tip, sleeve or both? And wouldn’t that just insulate the signal? Or am I trying to put extra pressure on a connection somewhere? Also, scotch, painters, gaff, electrical or am I just overthinking it? ;)
 
I’m not sure I understand what I’m testing for. Am I taping the tip, sleeve or both? And wouldn’t that just insulate the signal? Or am I trying to put extra pressure on a connection somewhere? Also, scotch, painters, gaff, electrical or am I just overthinking it? ;)
No, just tape the cable so you know which end is what!
 
Tried every combination. On the last one, it stopped working, but then everything was not working. But now it’s all fine again and I can’t find any setup that doesn’t work. I’m baffled, but I’ll keep the test in mind if it goes out again.

Thanks again!!!
 
I suspect a broken wire on your lead where it enters the Jack & it's Hit & Miss depending on the angle of the dangle.
If you were to bend the leads Left & Right, Up & Down where they enter the Jack you will probably get intermittent to no sound!
 
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