If the pedal functions fine with 1 guitar and poorly with a different guitar, the pedal isn’t the issue. Polarity reversal on the power would cause the pedal to be non-functional and in most cases, damage the pedal.
One possibility is the lead dress you dont want power wires running close to and in parallel with audio wires like this II
I'd remove those cable ties from the wiring and move the power wires away from your in and out wires you've got plenty of extra wire on there, so you should be able to separate and move them away from each other if you have to cross them over do it like this +
My guess is the hum is just a bit of interference from the pickups in the Strat and a lot of interference and a grounding issue in the Paul. Turning up distortion gain will most certainly amplify this and make it sound weird. I’d try checking out the guitars first
Hey we all have our “figuring it out” phase. I have some dumb stuff to admit to from then as well. Let’s just hope it’s not actually the pedal and we’re just idiots!
We're nice here and you showed us guitar pedal guts so we're glad to answer a question! Look into even a cheap isolated power supply if you use a few pedals on a daisy chain supply. Daisy chains are sold but shouldn't be used imo.
Thanks for the tip. I am using a power supply, which should be isolated. It's a budget one (Caline). However, the part that baffles me is that other pedals on the same supply don't have any issue.
I’m guessing that’s the battery clip wrapped in electrical tape (this is done to keep it from grounding out on the inside of the enclosure). Give a battery a shot and see if it behaves any differently.
Thanks for the replies, everyone! This is an amazing community. I've decided to get my guitar checked and possibly take the pedal to a local pedal maker to check the soldering.
I think it's high time to start learning more pedal diy, something I've been postponing for years.
https://preview.redd.it/y8j0ydf52xmc1.png?width=1116&format=png&auto=webp&s=8d5a9f49ed6aed5d6b9f8ebd31d69ec91bd9970a
I would start by checking the wiring. It should match this schematic. I can’t quite trace the wires in the picture, but from what I can see the green wire in the picture has been replaced by the bare wires to the two 1/4” jacks. There should be a connection directly to the ground of the pcb from that point on the 9V jack, so the fact that there isn’t could be your problem.
The big lug is ground, not positive. Pedal wouldn’t function if the polarity is reversed.
Edit: link
https://pcbguitarmania.com/wp-content/uploads/2019/03/Pedal-Wiring-Guide-1.pdf
If the pedal functions fine with 1 guitar and poorly with a different guitar, the pedal isn’t the issue. Polarity reversal on the power would cause the pedal to be non-functional and in most cases, damage the pedal.
Thanks for the reply. The part that got me is that other pedals on the same power supply work fine with the same guitar.
One possibility is the lead dress you dont want power wires running close to and in parallel with audio wires like this II I'd remove those cable ties from the wiring and move the power wires away from your in and out wires you've got plenty of extra wire on there, so you should be able to separate and move them away from each other if you have to cross them over do it like this +
Thanks for the tip. This is definitely worth trying. I see the same closeness on other RATs, but it doesn't hurt trying it so I will
It might not cure it completely, but it should help being that long those wires are like antennas
Do you have a multimeter?
Father in law has one. What should I check ?
My guess is the hum is just a bit of interference from the pickups in the Strat and a lot of interference and a grounding issue in the Paul. Turning up distortion gain will most certainly amplify this and make it sound weird. I’d try checking out the guitars first
100% I'm very confused that someone would think it's the pedal when one guitar works, and the other doesn't........isn't it obvious it's the guitar?
Hey we all have our “figuring it out” phase. I have some dumb stuff to admit to from then as well. Let’s just hope it’s not actually the pedal and we’re just idiots!
It's confusing because the guitar works fine with other pedals (newer ones) on the same power supply, no loud hum. That's what made me rethink.
We're nice here and you showed us guitar pedal guts so we're glad to answer a question! Look into even a cheap isolated power supply if you use a few pedals on a daisy chain supply. Daisy chains are sold but shouldn't be used imo.
Thanks for the tip. I am using a power supply, which should be isolated. It's a budget one (Caline). However, the part that baffles me is that other pedals on the same supply don't have any issue.
If you need more gut shots btw, let me know :)
The soldering is terrible but appears to be done correctly.
That's what made me wonder. Do you think it can have an effect on grounding or not?
If the connection is not complete or solder joint cold, possibly, but it wouldn't work, not what you described.
Polarity is correct stomp boxes have a negative tip. Sounds like there’s an issue with the guitar
i think these are center positive, i had to use a converter with my psu. at least my reissue big box was from around the same time
Read the post
I did. Looks like it has the same plug and is from around the same time?
I’m guessing that’s the battery clip wrapped in electrical tape (this is done to keep it from grounding out on the inside of the enclosure). Give a battery a shot and see if it behaves any differently.
Same with a battery. But I've noticed now that if you touch the footswitch with only the pedal plugged into the amp, no guitar, you get hum again.
If it’s center negative then tape makes no difference, the positive lead is switched.
Thanks for the replies, everyone! This is an amazing community. I've decided to get my guitar checked and possibly take the pedal to a local pedal maker to check the soldering. I think it's high time to start learning more pedal diy, something I've been postponing for years.
https://preview.redd.it/y8j0ydf52xmc1.png?width=1116&format=png&auto=webp&s=8d5a9f49ed6aed5d6b9f8ebd31d69ec91bd9970a I would start by checking the wiring. It should match this schematic. I can’t quite trace the wires in the picture, but from what I can see the green wire in the picture has been replaced by the bare wires to the two 1/4” jacks. There should be a connection directly to the ground of the pcb from that point on the 9V jack, so the fact that there isn’t could be your problem.
Center pin could be connected to any ground point, doesn’t necessarily need to be connected directly to the board.
This is very useful. Thanks for the advice. I'll have my pedal building friend go over it based on what you said.
Edit: deleted so you don’t accidentally follow my poor advice 😅
The big lug is ground, not positive. Pedal wouldn’t function if the polarity is reversed. Edit: link https://pcbguitarmania.com/wp-content/uploads/2019/03/Pedal-Wiring-Guide-1.pdf
That diagram is for how sensible people wire power. Unfortunately the pedal power standard is the opposite.