SOLVED Chop Shop - total oscillation annihilation! Help!

[Traynorbanger]

Hello all! This Chop Shop build was supposed to be my easy refresher before tackling more complex pcb's but this issue has me stumped....

THE ISSUE: it goes into crazy oscillation when adjusting the knobs (vol, sag, gain)...this occurs with or without input signal (see video)

I HAVE TRIED: reflowing components, moving around leads, checking 3pdt switch + jacks + ground for continuity

Been piecing it together 15 minutes at a time during breaks so its very possible I missed something.
Can you spot something basic that I'm missing? I've read about this problem with some high gain pedals but not the Chop Shop.
Audio probe will be next.
Any input is greatly appreciated, thank you!!

 

[Harry Klippton]

Are your jacks wired backwards? Looks like the white wire is connected to sleeves on the jacks and the green wire is from tip then going to ground on the PCB

 

[Brett]

Are your jacks wired backwards? Looks like the white wire is connected to sleeves on the jacks and the green wire is from tip then going to ground on the PCB

I'd start here. That appears to be problem number one. If you still have issues, then you probably want to investigate the foot switch/foot switch PCB. You may also want to consider trying to go a little leaner on the solder next time. It may be a symptom of trying to reflow things too quickly, but several of your solder joints could stand to be cleaned up a bit. Best of luck, I hope it's as simple as wiring!

 

[Laundryroom David]

How did you bias the jfets?

 

[Traynorbanger]

Ahh, I totally had the jacks wired backwards!!! Amateur hour!! Great catch, HK I so appreciate the support and lack of judgement in this community, thank you. It works now and sounds great.

As for biasing the jfets, I just....haven't. I'm hoping the j201's I got from PedalPCB will be sufficient as-is. There are some excellent posts here detailing the biasing process for the Chop Shop, I just haven't made the time to dial it in.

Thanks again

 

[Harry Klippton]

@Traynorbanger don't forget to mark this thread solved

 

[Traynorbanger]

@Traynorbanger don't forget to mark this thread solved

Thanks for the reminder.....I'm new to these parts, how do you mark a thread as "SOLVED"?

 

[Harry Klippton]

Thanks for the reminder.....I'm new to these parts, how do you mark a thread as "SOLVED"?

At the bottom left of your OP, there's a drop down to edit your post. Once in edit mode, there will be a drop down to the left of the thread title field where you can choose the flag that says "solved"

 

[Traynorbanger]

At the bottom left of your OP, there's a drop down to edit your post. Once in edit mode, there will be a drop down to the left of the thread title field where you can choose the flag that says "solved"

Dude, you're the best. Much appreciated.