Maelstrom troubleshoot – no sound (solved)

[Anonymous]

I am getting sound when bypassed. When engaged, I’m getting silence and no LED illumination.

I probed all power and audio paths with a DMM. The connection between R5, C6, and pin 6 of IC1 seemed intermittent. This may have been the probe not contacting cleanly, but I added a wire anyway to be safe. I also noticed that I need to flip D6 around. Otherwise, I have no idea what’s going wrong.

 

 

 

 

 

 

[Barry]

D6 Germanium looks backward compared to board silkscreen. Unless they are Russian diodes in which case D7 is backward.

[Anonymous]

Correct. I noted that on the OP. I’ve since fixed that. But that shouldn’t matter for this problem. When the SPDT switch is in any position, the outcome is the same.

[Barry]

There is no way for me to trace the wiring.

If you have made an audio probe you should make short work of the issue.

[Barry]

You can also use your DMM in Continuity mode to check that all the relevant points work as shown in the image below as well as any on board pads that might need verified.

[Anonymous]

Thanks, Barry. It was such a simple, stupid problem that I can’t believe I missed it. Barrel jack wired wrong. I need to change my reference sheet that uses the more conventional “ground” instead of “barrel.” I usually interpret it without thinking.

[Barry]

Great! We all make mistakes all the time. I cringe when people post about how many pedals they built correctly before telling us the symptoms. I have built probably 2,500 pedals and I still make mistakes.

So more importantly now how does it sound?

[Author]

Posts