So I recently built the parentheses fuzz circuit, it started out fine and I was pretty happy with tone but it was a little noisy. I started checking other threads and saw that people were using tantalum caps on C13, C14, and C15 to be closer to the EQD circuit so I decided I'd un-soldered those and put sockets in place so that I could compare the two components and see what I liked best. I also un-soldered the clipping led and put sockets there as well so I could experiment with the circuit. After doing all this I have a squealing noise that I can hear when playing and is very prominent when there is no input plugged into pedal. I plan to cleanup my wiring and check solder points but I'm not sure where the noise is coming from. Below is picture of pedal, I'll get a better shot once I clean everything up. Also a link to video of the problem sound. I hope I didn't fry a component or damage the board, I was very careful. I should have just left it alone, the tone was very nice.
Parentheses fuzz squealing noise
- Thread starter Tlsaudio
- Start date
Nostradoomus
Well-known member
I’m not at home but I’ll try to give you the idea...If your cable only had the black sleeved connection and the bare wire shield, I connect the black to hot input pad/jack, I then unravel and twist the shield up (and heat shrink over it) and solder that to ground points. Same idea as patch/guitar cables.
Chuck D. Bones
Circuit Wizard
Looks like you used shielded pair wire, should have been coax (one wire and a shield). The shield goes where the black wire is hooked up now. Don't bother changing that now, the in and out are far away from each other and everything else. From the video, the squealing is worse when the input is open-circuit. Try shorting the input.
Ok so i build a little audio probe and and marked all the spots on the board that i'm having the noise issue and also every ground point. The noise points are in Pink and the grounds are in Orange. I bypassed the Boost and Octave just to make sure they weren't the cause but i'm still getting lost trying to pinpoint where the issue starts. It's really hard to trace path on a populated board. Anybody have a sec to help out? The noise seems to be centralized in the Rat section but im not so sure that it couldn't be from another issue elsewhere on my part but this is a good starting point
Attachments
I pulled Q5 and it went away in some spots so that is not the issue. If i pull the IC it goes away completely but then that kills most everything in the circuit so i don't think that's the issue. I have also swapped the IC's with other working ones and problem still remains. Dont know if any of that helps
Attachments
diocide
New member
I was poking around my builds that are giving me issues and I noticed that when I poked around the two GE diodes, the noise would change. I thought maybe I had a bad solder joint on them, so I heated them up while the pedal was on, and in full squeal. On the input side, when I heated the pad, the noise would go away. I thought it was cured. But within about 10-15 seconds (how long I assume it takes for the pad and solder to cool down) the noise would return.
Now this is really strange.
Now this is really strange.
I tried different variations of shielding/non shielding and there was no change in anything. I've bypassed the octave and boost and traced out the whole circuit and the issue seems to be in the Rat side but looks like the signal gets split going to the octave so not sure exactly where its coming from. It's either a bad resistor,cap, or grounding issue. Swapped multiple working IC's and still same problem. Anything im missing? One thing i couldn't figure out from my trace is how the signal gets back from the diode clipping section, i'd like to know just for my own personal knowledge
Attachments
Hi,
I've got the same issue with parentheses mini. I've tried re-soldering, changing ICs, swapping diodes... and nothing helped. I did checkup by connecting audio output to different circuit stages and traced it down to feedback loop into input stage. I could hear clean signal and tiny bit of heavily distorted signal, just after Q1. It feedbacks from somewhere after the filter (feedback changed character when turning filter pot even if measured before pot). Components seem to be fine (measured everything with component checker), so it may be some mechanical/grounding issue. My last suspect are switches leaking signal, but I didn't yet have time to check this. Other than that I'm out of ideas. Maybe this will help you to trace this down.
I've got the same issue with parentheses mini. I've tried re-soldering, changing ICs, swapping diodes... and nothing helped. I did checkup by connecting audio output to different circuit stages and traced it down to feedback loop into input stage. I could hear clean signal and tiny bit of heavily distorted signal, just after Q1. It feedbacks from somewhere after the filter (feedback changed character when turning filter pot even if measured before pot). Components seem to be fine (measured everything with component checker), so it may be some mechanical/grounding issue. My last suspect are switches leaking signal, but I didn't yet have time to check this. Other than that I'm out of ideas. Maybe this will help you to trace this down.
Chuck D. Bones
Circuit Wizard
Here's where I think the problem lies: The input and output of the pedal section are very close to each other and it's easy to get stray coupling between them. Q1 is the input buffer, it's right next to the AMPLITUDE control.
I would recommend that you shorten Q1's leads as much as possible. Ditch the socket, you don't need it.
The AMPLITUDE pot's leads need to be very short and kept away from Q1. Same goes for the FILTER pot's leads. You really should be using pots with PC pins or if you insist on using solder-lug pots, solder short bare wires between the solder lugs and the board so you end up with the equivalent of PC pins.
Standing resistors up turns them into little antennas. R1 in particular should not be standing up.
When you finally get it all working, try turning D2 & D3 around. They are backwards in the build docs and silk screen (and apparently EQD's v1 pedals). Some pedals work with them backwards IF those two diodes are leaky enough.
This is a finicky pedal, it seems to dominate the Troubleshooting forum. This pedal requires the utmost care in assembly. There are plenty of successful builds out there. Go look in the Build Reports forum. When your board looks like the ones built by ChongMagic & K Pedals, it will work - no problem.
I would recommend that you shorten Q1's leads as much as possible. Ditch the socket, you don't need it.
The AMPLITUDE pot's leads need to be very short and kept away from Q1. Same goes for the FILTER pot's leads. You really should be using pots with PC pins or if you insist on using solder-lug pots, solder short bare wires between the solder lugs and the board so you end up with the equivalent of PC pins.
Standing resistors up turns them into little antennas. R1 in particular should not be standing up.
When you finally get it all working, try turning D2 & D3 around. They are backwards in the build docs and silk screen (and apparently EQD's v1 pedals). Some pedals work with them backwards IF those two diodes are leaky enough.
This is a finicky pedal, it seems to dominate the Troubleshooting forum. This pedal requires the utmost care in assembly. There are plenty of successful builds out there. Go look in the Build Reports forum. When your board looks like the ones built by ChongMagic & K Pedals, it will work - no problem.
Chuck D. Bones
Circuit Wizard
Try everything else first. If that still doesn't fix it, get different resistors, at least the ones near Q1. I get mine from DigiKey (RNMF14FTC series) and Tayda (Royalohm 1/4W or 1/8W MF). I try to make sure the parts will fit the board before I buy. The best suppliers provide datasheets.