Duocast issues...

[glowboy]

Okay I’m stuck now. I built this Duocast and cannot get signal out of it. The bypass works, LEDs come on, but once pedal is turned on, it cuts the full signal. I’ve built several PCBs from PedalPCB and first one I’m stuck on. Things I’ve tried already, checked the pin outs on the OC71, flipped the IC just in case, reflowed all of the solder joints, traced the signal as much as I could without a audio tracer. Parts came from Tayda, transformer from Digikey, and OC71 from Tube Depot. I’m honestly just stuck at this point and any help is much appreciated.

 

[Dan0h]

Can’t tell from the pic but did these two bridge over with solder? FS under transformer.

 

[glowboy]

Can’t tell from the pic but did these two bridge over with solder? FS under transformer.

No they aren’t connected but there is a little black paint missing between them. Think that would affect anything?

 

[Dan0h]

No they aren’t connected but there is a little black paint missing between them. Think that would affect anything?

I’m not sure. That’s the only thing that stuck out to me, because it looked like it could have been bridged. I’m still a noob myself wish I could offer more suggestions.

 

[BuddytheReow]

I see trimmers. Is this to bias? Do you have power to the IC?

 

[glowboy]

I see trimmers. Is this to bias? Do you have power to the IC?

The trimmers are bass and treble controls for the second gain stage. I will check to see if there is power to the IC.

 

[glowboy]

Finally figured it out! My new multimeter with a transistor tester on it just came in and I pulled the OC71 to find out it was DOA. Had a spare Russian unmarked PNP ge transistor from a Tonebender build. Tossed it in and success!!! The hFe of the Russian transistor is around 95 so it’s a little too hot, but it works. I have some NTE transistors coming in for another build and will have some spares from that. Since it’s still socketed I’ll swap around to find one I like.

Thanks for the help everyone!