Pitch pirate clone debugging

[seten]

I recently finished a pitch witch from PedalPCB and I'm having some problems. The onboard LED is working and pulsing as it should and is responding to the wave/speed/rate pots. With feedback and blend all the way up I'm getting a weird feedback oscillation kinda white noise that I put on soundcloud below. But no guitar signal when unless the effect is bypassed. What should I check? already double checked all my connections and wiring.

https://soundcloud.com/sethpeakock777/pitch-witch-debugging

[patrick398]

Post schematic if possible, that'll make it a hell of a lot easier for people to help.
Sounds like the LFO is working. Do you have an audio probe?

[seten]

Post schematic if possible, that'll make it a hell of a lot easier for people to help.
Sounds like the LFO is working. Do you have an audio probe?

Geez. I think Ive forgotten the schem every time ive posted on here.

https://www.pedalpcb.com/docs/PitchWitch.pdf

Nope, but I just looked it up and I can definitely make one!

[patrick398]

Definitely worth making an audio probe, can save you a lot of time and headaches.
You should have signal at pin 2 and 5 of IC1, that clean signal should also get getting to pin 15 and 16 of the PT2399, and the delay signal coming out of pin 14.
Clean signal and delay meet at blend pot so you should have a mix on the wiper. I'm sure you know all this but just in case
Hope you get it sorted

[seten]

Definitely worth making an audio probe, can save you a lot of time and headaches.
You should have signal at pin 2 and 5 of IC1, that clean signal should also get getting to pin 15 and 16 of the PT2399, and the delay signal coming out of pin 14.
Clean signal and delay meet at blend pot so you should have a mix on the wiper. I'm sure you know all this but just in case
Hope you get it sorted

Thanks for the reply! I actually didnt know any of that. Verrrry new. I made the probe ans I think I might have found the problem. i have signal on the pin of the trimmer directly connected to the circuitboard "in" but not on any of the other pins. i know the middle pin is supposed to be connected to ground so i woildnt get any signal there but shouldnt i have signal on the third pin?

[ElectricDruid]

i have signal on the pin of the trimmer directly connected to the circuitboard "in" but not on any of the other pins. i know the middle pin is supposed to be connected to ground so i woildnt get any signal there but shouldnt i have signal on the third pin?

The middle pin is supposed to go to the LM386 pin 2. It's the other end which connects to ground. Depending on the trimmer position, you should have signal on that middle pin too.

HTH,
Tom

[patrick398]

Are your ICs in sockets? Do you get signal at pin 2 of the trimmer with the LM386 removed?
Check for a solder bridge between pin 2 and 3 of the LM386 on the solder side of the board or test for continuity between them with a multimeter. Since you get no signal at pin 2 of the trimmer or pin 2 of the LM386 it's possible it's shorted to ground via pin 3. Could be a hundred different things but i'd check that first.

Might be an idea to post some pictures too, top side and bottom side of the board

[seten]

thanks so much for all the replies! ive got delay! but the pitch shifting wont work.

My trimmer started working, and then stopped, and then i reflowed the solder joint and it worked, then stopped again, etc. Not sure whats wrong with that but ill worry about that at the end. its currently working fine, if i have to ill just jumper it and then replace the trimpot at the end. i leave my pitch pirate with gain on full anyway.

I found out I need a jumper from  R2 to C4, and that fixed the delay. (I want to make sure im jumpering the right side though, both sides give me signal but the way i understand it if im choosing the wromg side of C4 then im essentially bypassing C4. How do I find the right side? I cant follow the trace since my board is filled up. On the schematic theyre all labelled "1" and "2", is 1 the side on the left ans 2 the right when looking at it with the printed component values right side up?)
thank god i dont need to replace my pt2399. but now theres no chorus/pitch shifting effect, the depth knob does absolitely nothing. I cant figure out how that section of the schematic works and it seems to be separate from the direct signal path so i dont think i could use my audio probe.

[patrick398]

It sounds like you have some bad solder joints. You fixed, partially anyway, the problem with the trimmer by re-flowing the solder. I'd suggest doing this on any joints that aren't nice and shiny.
Here is a good page on good soldering technique:
http://www.technologystudent.com/elec_flsh/new_pcb1.html

I found out I need a jumper from  R2 to C4, and that fixed the delay. (I want to make sure im jumpering the right side though, both sides give me signal but the way i understand it if im choosing the wromg side of C4 then im essentially bypassing C4. How do I find the right side?

You shouldn't need to jumper any components. It sounds like either R2 or C4 aren't making connection, try re-flowing the solder on these joints. Also check R2 is the right value, you could have accidentally put a much larger value in there so signal can't pass.

I guess it's possible the trace between these two components got damaged by excessive heat or something but it's unlikely.