Guitar Hum
Moderators: JMPGuitars, Daviedawg, Graydon, CurtissRobin, zaphod_phil
- TriodeLuvr
- Frequent poster
- Posts: 639
- Joined: Tue 10/16/18 11:19 am
Guitar Hum
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
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
0 x
-
- Superior Amp Tech
- Posts: 769
- Joined: Fri 01/08/10 2:00 am
- Location: Scotland
Re: Guitar Hum
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
Dd
1 x
- Bieworm
- Verbose Moderator
- Posts: 2423
- Joined: Mon 02/10/20 8:24 am
- Location: Belgium
Re: Guitar Hum
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.
0 x
"THIS should be played at high volume..preferably in a residential area"
- TriodeLuvr
- Frequent poster
- Posts: 639
- Joined: Tue 10/16/18 11:19 am
Re: Guitar Hum
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
Jack
0 x
- Bieworm
- Verbose Moderator
- Posts: 2423
- Joined: Mon 02/10/20 8:24 am
- Location: Belgium
Re: Guitar Hum
Sometimes getting rid of that noise is insane. The lead dress and grounding saga continues from amp to guitar..TriodeLuvr wrote: βMon 03/01/21 12:24 pmThanks 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
0 x
"THIS should be played at high volume..preferably in a residential area"
- JMPGuitars
- Super Duper Admin
- Posts: 4128
- Joined: Tue 09/18/12 8:00 pm
- Location: South Central, MA
- Contact:
Re: Guitar Hum
I use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.
1 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale
- Bieworm
- Verbose Moderator
- Posts: 2423
- Joined: Mon 02/10/20 8:24 am
- Location: Belgium
Re: Guitar Hum
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 ..JMPGuitars wrote: βMon 03/01/21 2:20 pmI use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.
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
0 x
"THIS should be played at high volume..preferably in a residential area"
- JMPGuitars
- Super Duper Admin
- Posts: 4128
- Joined: Tue 09/18/12 8:00 pm
- Location: South Central, MA
- Contact:
Re: Guitar Hum
I guess I'm always perfect, because I've never had an issue.Bieworm wrote: βMon 03/01/21 2:26 pmThat 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 ..JMPGuitars wrote: βMon 03/01/21 2:20 pmI use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.
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
1 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale
- Bieworm
- Verbose Moderator
- Posts: 2423
- Joined: Mon 02/10/20 8:24 am
- Location: Belgium
Re: Guitar Hum
You're bound to be perfect at this kinda stuff. It's a curseJMPGuitars wrote: βMon 03/01/21 2:29 pmI guess I'm always perfect, because I've never had an issue.Bieworm wrote: βMon 03/01/21 2:26 pmThat 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 ..JMPGuitars wrote: βMon 03/01/21 2:20 pmI use full copper shielding in guitars, and especially anything with single coils. Definitely make sure the ground wire is good as Dd mentioned.
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
1 x
"THIS should be played at high volume..preferably in a residential area"
- JMPGuitars
- Super Duper Admin
- Posts: 4128
- Joined: Tue 09/18/12 8:00 pm
- Location: South Central, MA
- Contact:
Re: Guitar Hum
Perfect would be a curse. There's no room for growth.
1 x
'I installed a skylight in my apartment yesterday... The people who live above me are furious.' - Steven Wright
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale
Modern Ground Schemes
Soldering Technique
B+ Voltage Reduction
Amplifier Tools & Parts Info
Web Design: DolceVittoria.com
Guitars / Amps / Effects: JMPGuitars.com
(anti)Social: Facebook Β· Instagram
Items for Sale