Backfeeder Momentary Footswitch

[knobToucher]

I posted on the first revision of the forum that I was having trouble generating feedback with the momentary FS...

I recently got a new soldering iron and decided to reflow all the connections just in case shoddy soldering might be the culprit. Once I'd done that I connected it all up but was experiencing the same problem. I held the FS down and started touching the connections on the back of the board near where the momentary is wired up (so basically all the transistors) and got some weird modulates pitch noises. After I did that the FS miraculously started working!!

So I just wanted to put this out there and ask if maybe this is a grounding issue or something? The PCB is not in an enclosure, all the inputs/outputs are wired to their spots on the board. However, I'm getting power by connecting the 9V positive and ground to a speaker wire terminal that is connected to a regular plastic DC socket. Do you think if I box her up my issues might disappear?

 

[zgrav]

Are you saying after you unboxed the effect and reflowed the solder it is now working, and you wonder whether it was not working before because it was boxed. If it works when unboxed you should be able to get it working when it is boxed. Give it a try. If it does not work when you put it back in the box you start looking for places where the PCB, the wires, the jacks or the pots might be touching the case or are being squished together. You also need to make sure your power jack is insulated from the case since the outside ring on the power jack is live.

 

[knobToucher]

Sorry my post is confusing! No, the effect has never been boxed. I've been struggling to get the effect working outside of the enclosure for a long time, the momentary FS/Feedback part that is. And all of a sudden after simply touching a few connections on the rear of the PCB with my finger the momentary switch is now producing feedback. I was wondering why this might be? Grounding?

 

[zgrav]

You could have had a bad solder connection on any one of the places that you retouched. Try boxing it and see if it works, and if it does not follow the suggestions in my earlier post.

 

[knobToucher]

You could have had a bad solder connection on any one of the places that you retouched. Try boxing it and see if it works, and if it does not follow the suggestions in my earlier post.

Ok thanks. Just to be even clearer though..

1. Completed initial soldering
2. Tested, FB not working
3. Retouched connections
4. Tested, FB still not working
5. Dragged my finger across the underside of the PCB where the row of transistors are connected
6. Test again, now FB works.

So yeah I guess I might test it again later, hopefully it just works without having to touch connections on the back of PCB first! Weird. Thanks for your help though

 

[zgrav]

My guess is that luck like that is usually temporary, but it suggests you should also touch up the solder for the transistors. Also possible there is some break in a trace on the pcb, but see what happens if you get it boxed.