# Parentheses fuzz squealing noise



## Tlsaudio

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.


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## Tlsaudio

Here's the only pic I have for now


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## Tlsaudio

And here's video of pedal prior to changing stuff


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## Chuck D. Bones

Long leads on the controls can cause unwanted coupling and oscillation.  You might consider getting board-mounted pots next time.  If you laid out the front panel in accordance with the drill template, then you can use the existing pots with very short wires, like 1/4".  The noise I'm hearing is 120Hz hum.  Try closing the box and see if it goes away.


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## Tlsaudio

Chuck D. Bones said:


> Long leads on the controls can cause unwanted coupling and oscillation.  You might consider getting board-mounted pots next time.  If you laid out the front panel in accordance with the drill template, then you can use the existing pots with very short wires, like 1/4".  The noise I'm hearing is 120Hz hum.  Try closing the box and see if it goes away.



Thanks, I'm going to clean everything up asap and see if it helps. If I adjust the tone or the distortion amount the pitch of the noise changes if that means anything


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## Chuck D. Bones

Tells me that signal is getting fed back from the output to the input. Shortening the wires should help.


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## Tlsaudio

Chuck D. Bones said:


> Tells me that signal is getting fed back from the output to the input. Shortening the wires should help.


One more question before I start. Since I didn't use the pcb mount pots should I use shielded cable to all controls? Would that help along with shortening the cables? Im going to use sheilded cable for inputs and outputs so I have some available


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## Nostradoomus

Just the in/outs should be fine. Most of the time shielded wire isn’t necessary but i use it on high gain pedals such as this.

Mount all your wiring to pots and toggles and LEDs from the other side of the board to keep them as short as possible and you should be good to go. Snip your tantalum cap/diode legs as well so they fit flush in the sockets.


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## Chuck D. Bones

Yep, what Nostradoomus said.  There is a thread on one of the forums here on how to board-mount pots with solder lugs.  Maybe someone can point you to it, I got frustrated looking for it and gave up.  Basically, use solid wire on the pots to make the equivalent of PC pins and then mount them as shown in the Basic Workflow Tips.


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## Nostradoomus

I just end up using old clipped resistor and diode leads. Use the longest ones you can find, mount the pots to the enclosure with the long leads soldered on and line em up, solder em in and snip the excess. If you used the drill template the toggle switch should line up too, try that one first.


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## Nostradoomus

This is one of the times I use those cheesy helping hands! 









						7915-FCA0-C5-B3-41-AD-82-DD-A46598460536
					

Image 7915-FCA0-C5-B3-41-AD-82-DD-A46598460536 hosted in ImgBB




					ibb.co


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## Tlsaudio

Chuck D. Bones said:


> Tells me that signal is getting fed back from the output to the input. Shortening the wires should help.


Dang still got the weird noise even after making lines as shorts possible. The overall tone is not bad but I can tell it's there whenever I get into the highest gain setting and especially when octave is on. I'll get some better pics and video when I get back from holidays. I appreciate all the help


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## Tlsaudio

Nostradoomus said:


> Just the in/outs should be fine. Most of the time shielded wire isn’t necessary but i use it on high gain pedals such as this.
> 
> Mount all your wiring to pots and toggles and LEDs from the other side of the board to keep them as short as possible and you should be good to go. Snip your tantalum cap/diode legs as well so they fit flush in the sockets.


I used the sheilded cables on input and output and noise is still there, maybe I didn't do something right with the sheild but I'll get better pics and video when I get back from holiday. Appreciate the help though


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## Tlsaudio

Chuck D. Bones said:


> Tells me that signal is getting fed back from the output to the input. Shortening the wires should help.



Ok I cleaned everything, shortened all leads and checked all solder joints but still getting noise. I used sheilded cable for in and out but not sure if I was supposed to connect sheild to something. Not sure where to start with troubleshooting. I took some better pics and another video of what weird sounds, any help is appreciated


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## Tlsaudio

Here's what it is doing, squealing when input is not connected. It's also noticeable when playing but not as loud


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## Nostradoomus

Most likely you have a cold solder joint somewhere...visual inspection of your joints is crucial. Put your boss tuner in front of it and see if that squelches the noise for now, often times a buffer will cure this.


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## Tlsaudio

Could this type of noise be caused from the dpdt switch in the rat section? I think 8 might try to bypass it but not exactly sure how.


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## Tlsaudio

Nostradoomus said:


> Most likely you have a cold solder joint somewhere...visual inspection of your joints is crucial. Put your boss tuner in front of it and see if that squelches the noise for now, often times a buffer will cure this.



I hit every solder joint again, defluxed board, changed dpdt switches and tried the buffer in from and no luck still squeels when input is disconnected. I also checked path with audio probe and continuity with multimeter....I'm stumped. Pedal sounds good but I can tell it's not right, you can here the squeal coming through and especially if I get into higher gain settings. I'm thinking its a ground issue with something in the rat circuit or possibly something getting crossed in the boost or octave but I can't find it. On the plus side I did an Acapulco gold clone and really digging it so probably going to try the full Model-t preamp circuit. Is Rat in the life pedal just a normal rat or is modified? Maybe I'll just try to build it alone. It's a shame because I'm getting some insanely heavy tones by itself and also stacking it with the AC gold.


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## Nostradoomus

Very strange. I generally use single conductor shielded cable with the sleeve as ground, not certain it would help this situation to do that!


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## Tlsaudio

Nostradoomus said:


> Very strange. I generally use single conductor shielded cable with the sleeve as ground, not certain it would help this situation to do that!


Any chance you could snap a pic of how that's connected? I tried the shielded cable but not sure I did it right. I used two conductor sheilded but stripped back shield


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## Tlsaudio

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.


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## Nostradoomus

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.


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## Chuck D. Bones

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.


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## diocide

Did you ever get this resolved? I’m getting the same issue on two builds as well.
The octave pot and sweep pot seem to create a feedback loop.


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## Tlsaudio

diocide said:


> Did you ever get this resolved? I’m getting the same issue on two builds as well.
> The octave pot and sweep pot seem to create a feedback loop.


I haven't but I'm still trying to figure it out


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## Tlsaudio

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


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## Tlsaudio

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


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## diocide

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.


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## Barry

Heat will effect GE diodes, might want to try and change them


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## diocide

Barry said:


> Heat will effect GE diodes, might want to try and change them


I plan to socket then and try others. Weird.


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## Tlsaudio

diocide said:


> 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.


I find on mine that grounding certain components gets rid of noise but yours could also be a cold solder joint


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## Tlsaudio

diocide said:


> I plan to socket then and try others. Weird.


And def socket the diodes and transistors they are pretty delicate


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## Tlsaudio

diocide said:


> I plan to socket then and try others. Weird.


Also I have no idea what im really talking about lol, this stuff is way over my head but it's fun to mess with and learn something new


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## Tlsaudio

Chuck D. Bones said:


> 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.


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


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## pegasus

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.


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## Tlsaudio

Again here's where I'm having issues, could really use some help. Thanks


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## Chuck D. Bones

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.


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## Tlsaudio

Chuck D. Bones said:


> 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.


Thanks so much, i will try all of this. unfortunately the resistors i bought have a weird coating on one side but ill try to get them as short and flat as possible


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## Chuck D. Bones

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.


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## Tlsaudio

Chuck D. Bones said:


> 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.


Will do I'll report back asap. Thanks again I really appreciate it


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