Boneyard Compressor+Plumes Distortion High Pitch Squeal Issues?

[Champagneperfume]

Greetings!

I built a 2-in-1 (signal chain flipper footswitch as well) pedal, the Delegate Boneyard Edition Compressor and the Greengage Overdrive. I get an obnoxious high pitch squeal when the Greengage/Plumes is on, goes away when off, goes away when both effects are engaged. The whistle kicks in when the pots on the Greengage pass about 70% rotation. Other than the gnarly whistle, it works like a charm.

I've read up on some other posts about electromagnetic interference noise coming from the charge pumps in each respective pedal as the culprit.

I chased through and around the Plumes/Greengage Overdrive with a Boss Looper, Rattlesnake Audio-probe, and a Scarlett audio interface into my MacBook...and the harsh squeal noise goes away ENTIRELY.

This noise only returns when I'm using an electric guitar (Fender Player Jaguar with stock pickups, I've also tried with a 2005 Mexican Telecaster with stock pickups and had the same result) that uses that previously mentioned set up. I've also tried it into a Vox AC-15 instead of the Scarlett audio interface and the results are basically identical.

I'm wondering if this an issue with the pickups and multiple unshielded wires? I can make the whistle go away for a minute if the pcb is in perfect position, but it's such a delicate spot and returns to the hellish screech very quickly. I ordered shielded wire so I'll be trying that as well.

Anyone got any clues or ideas?

I was planning on experimenting with pot values, measuring the Ohms at the spot where the noise kicks in and adjust it accordingly. That and the shielded wires.

 

[mzy12]

This should be eminently solvable.

Fist, add a bypass cap (100nF) directly from the 9v positive input on the power jack to the enclosure. Use the ground lug of the input jack in this case. This has solved, "whistling," noises on my pedals before. This is especially important when you've got a 1044 IC creating -9v, you have to make sure your power is as clean as possible. On that note, it's also important to keep your 9v and power ground wires as short as is reasonably possible, but it looks like you've done a decent job on that front.

If that doesn't work, you've also definitely got a ground loop going on. Remove the ground wire on the output lug. Add a star/tooth washer to it, which will help make the ground connection to the jack itself. You should also add one to the input jack, just as a general rule to help ensure a good mechanical/electrical connection to the enclosure.

 

[fontoponto]

and/or check the opamp. I had a nasty whine in a ts style od even in bypass and a switch from tl072ip to ne5523 solved the issue.

 

[mzy12]

and/or check the opamp. I had a nasty whine in a ts style od even in bypass and a switch from tl072ip to ne5523 solved the issue.

That certainly is an interesting option, but, in my opinion, changing a high impedance JFET opamp to low impedance BJT opamp is not so much solution in this particular instance as it is a mod that is done tubescreamer circuits. I imagine the noise went away due to the differences in current consumption of the ICs.

 

[fontoponto]

Thank you for the explanation. I don't want to hijack this thread but are there other options to eliminate squeeling in this circuit? https://moodysounds.com/wp-content/uploads/2020/04/hjart-muller-kit-sve2c.pdf

 

[mzy12]

Honestly, it's probably the same or similar to this. Looking at the schematic, it doesn't include a 100nf film/ceramic cap from 9v to ground. I recommend doing as I mentioned earlier, taking the +v lug of the input jack and connecting a 100nF cap from it to the chassis, as close as possible. I do this with a small screw I drill into the enclosure plus a star washer, solder tab and nut to ensure a good, solid connection on my builds currently. (I also do this because I use isolated jacks, but that's for a reason separate to the topic at hand). You can also do this with the input jack, if it's close by.

The reason for this is both simple and complex-ish at the same time. Simple, in that the reason for the 100nF cap is that due to a film/ceramic caps low ESR, it's better for high frequency filtering than an electrolytic cap. The complex part has to do with how AC signals, EMI and RF works. Basically, you want both power and ground to be at the same AC potential so that an AC signal 'sees' power and ground as the same, which is a little counter-intuitive at first blush, but makes sense if you do AC equivalent circuit analysis.

 

[fontoponto]

Dang it you are right, I forgot it because I was stupid enough to just copy it. Will try!

 

[mzy12]

It's not stupid to copy a build guide . It's hard to underestimate the hours I've spent in college and online figuring this stuff out. I don't think it's fair to expect everyone in the pedal building hobby to also go to college to do electrical engineering in order to figure out best practices! That's why the forums are here, and I must hand it to everyone for keeping things scientific and measurable when it comes to this stuff. I've learnt a lot from here and diystompboxes, and I've still got tons left to learn.

 

[airbud]

This should be eminently solvable.

Fist, add a bypass cap (100nF) directly from the 9v positive input on the power jack to the enclosure. Use the ground lug of the input jack in this case. This has solved, "whistling," noises on my pedals before. This is especially important when you've got a 1044 IC creating -9v, you have to make sure your power is as clean as possible. On that note, it's also important to keep your 9v and power ground wires as short as is reasonably possible, but it looks like you've done a decent job on that front.

If that doesn't work, you've also definitely got a ground loop going on. Remove the ground wire on the output lug. Add a star/tooth washer to it, which will help make the ground connection to the jack itself. You should also add one to the input jack, just as a general rule to help ensure a good mechanical/electrical connection to the enclosure.

I think this might be the issue with my data corrupter... it's the first textured paint enclosure I've used...

 

[airbud]

Greetings!

I built a 2-in-1 (signal chain flipper footswitch as well) pedal, the Delegate Boneyard Edition Compressor and the Greengage Overdrive. I get an obnoxious high pitch squeal when the Greengage/Plumes is on, goes away when off, goes away when both effects are engaged. The whistle kicks in when the pots on the Greengage pass about 70% rotation. Other than the gnarly whistle, it works like a charm.

I've read up on some other posts about electromagnetic interference noise coming from the charge pumps in each respective pedal as the culprit.

I chased through and around the Plumes/Greengage Overdrive with a Boss Looper, Rattlesnake Audio-probe, and a Scarlett audio interface into my MacBook...and the harsh squeal noise goes away ENTIRELY.

This noise only returns when I'm using an electric guitar (Fender Player Jaguar with stock pickups, I've also tried with a 2005 Mexican Telecaster with stock pickups and had the same result) that uses that previously mentioned set up. I've also tried it into a Vox AC-15 instead of the Scarlett audio interface and the results are basically identical.

I'm wondering if this an issue with the pickups and multiple unshielded wires? I can make the whistle go away for a minute if the pcb is in perfect position, but it's such a delicate spot and returns to the hellish screech very quickly. I ordered shielded wire so I'll be trying that as well.

Anyone got any clues or ideas?

I was planning on experimenting with pot values, measuring the Ohms at the spot where the noise kicks in and adjust it accordingly. That and the shielded wires.


View attachment 72844View attachment 72842
View attachment 72843

what power supply are you using? i had a charge pump whine at high gain with the Celsius CE-1 preamp, and a higher quality power supply solved it.

 

[mzy12]

I use

I think this might be the issue with my data corrupter... it's the first textured paint enclosure I've used...

Sand away any paint on the inside of the enclosure where you're making ground, probably the audio jacks for you.

what power supply are you using?

Either a palmer pwt12 mk 2 or a 1spot cs 12 I repaired, cos I have too many pedals haha.

i had a charge pump whine at high gain

Same here, when I used the variable voltage outputs of my pwt12. You defo need a good power supply to deal with them. It's frustrating how expensive those have gotten recently.

 

[fontoponto]

Honestly, it's probably the same or similar to this. Looking at the schematic, it doesn't include a 100nf film/ceramic cap from 9v to ground.

Yes, yes that was the problem... Thanks for pointing it out!

 

[JTEX]

Sounds to me like the classic issue of high gain and high input impedance, and a layout that brings an output wire (or trace) too close to the sensitive input path. You get parasitic capacitive coupling between them (positive feedback) and you've just made yourself a nice oscillator. Try using shielded input wire. You may even have to shield the input jack (I've seen it done in some commercial products, RME, Rockman etc). Also, watch out for true bypass wiring/switches, they bring input and output signals close together. Experiment with some strategically placed bit of aluminum or copper foil (connected to ground!) to see where you can place it to kill the squeal. Then do a more permanent fix.