Guitar Hum

[TriodeLuvr]

I'll start by admitting that I'm probably the worst guitar player you'll ever meet. I had a Harmony Stratotone when I was 13, then later acquired a Fender Jag. After 12 years of playing, I still stunk, so finally I quit. That was in the '70s.

Fast-forward to sometime in 2010, I realized my talent had improved with age. So, I bought a Peavey Predator and cobbled together a homemade amp from my tube amplifier hobby. Sadly, it turned out my playing wasn't better. I did discover that improvement was possible, but also that I didn't have the time. The Peavey went into storage.

Last year, my daughter decided to learn guitar, so the Peavey came out of hibernation. We bought a used, low power solid-state practice amp a few months later, then a kind person on Craigslist gave me a Peavey combo case with no amp. I've just installed a high gain Marshall-esque 36W amp into the case, and now we can really hear what this guitar sounds like. This leads me to my question, which has nothing to do with anything you just read except the guitar itself. It's a U.S.-made Peavey Predator from the '90s.

My question is whether the Peavey has something wrong with it, because it hums. I don't hear the hum on the Low input of the Marshall clone, but its raspy loud on the High input. I can also hear it on the practice amp. The hum cleans up completely when I touch the outer shield of the output plug on the guitar.

I don't know other musicians locally, so I'm hoping someone here will recognize this as a common symptom of something that's straightforward to fix. All help and advice will be much appreciated!

Jack

[Daviedawg]

That is a strat style guitar I think. Single coils can be very noisy when close to the amp. Assuming you have eliminated that as the source it sounds like the bridge earth is not grounded well or at all. You can test by pulling out the output jack and croc clipping the bridge or strings to the shield of the cable. Check the soldered connection from the spring claw in the same way.

Dd

[Bieworm]

What kind of hum? Because the kind of noise from single coils don't sound like real hum to me.. it's more high frequency hissy hum.

[TriodeLuvr]

Thanks Dd, I'll check that out later today. Bieworm, that's it exactly, a high-pitched buzz. I seem to remember opening it up when I first got it in order to spray the controls with Deoxit. And I think someone had been in it before me. Maybe there's a broken ground wire or something.

Jack

[Bieworm]

Thanks Dd, I'll check that out later today. Bieworm, that's it exactly, a high-pitched buzz. I seem to remember opening it up when I first got it in order to spray the controls with Deoxit. And I think someone had been in it before me. Maybe there's a broken ground wire or something.

Jack

Sometimes getting rid of that noise is insane. The lead dress and grounding saga continues from amp to guitar..

[JMPGuitars]

I use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.

[Bieworm]

I use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.

That is true... but if it's done anything less than perfect it's only going to emphasize the problem. Then the shielding acts as a giant RF magnet ..
I had to remove the shielding off the pickguard once because it got static as hell...
Ever tried shielding a jazzmaster? Those pickups are huge single coils.. next to impossible to shield that one. And when you shield the inside of the pickup cover it looses every bit of the trebly sparkle that makes the jazzmaster sooo nice

[JMPGuitars]

I use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.

That is true... but if it's done anything less than perfect it's only going to emphasize the problem. Then the shielding acts as a giant RF magnet ..
I had to remove the shielding off the pickguard once because it got static as hell...
Ever tried shielding a jazzmaster? Those pickups are huge single coils.. next to impossible to shield that one. And when you shield the inside of the pickup cover it looses every bit of the trebly sparkle that makes the jazzmaster sooo nice

I guess I'm always perfect, because I've never had an issue.

[Bieworm]

I use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.

That is true... but if it's done anything less than perfect it's only going to emphasize the problem. Then the shielding acts as a giant RF magnet ..
I had to remove the shielding off the pickguard once because it got static as hell...
Ever tried shielding a jazzmaster? Those pickups are huge single coils.. next to impossible to shield that one. And when you shield the inside of the pickup cover it looses every bit of the trebly sparkle that makes the jazzmaster sooo nice

I guess I'm always perfect, because I've never had an issue.

You're bound to be perfect at this kinda stuff. It's a curse

[JMPGuitars]

You're bound to be perfect at this kinda stuff. It's a curse

Perfect would be a curse. There's no room for growth.