Troubleshooting a Noisy Guitar Amp

davidhoffmanmusic · Post by **davidhoffmanmusic** » Wed Feb 22, 2012 4:31 pm

A Fender Blues Jr., to be specific. Trying to do some home recording, and It's driving me crazy - great tone, but tones of background noise. Guitar has humbucking pickups.

What are the potential causes, and how can I test each? Bad tube? fuzzy power lines in the room? (it is track lighting on rheostats, but turning them off doesn't seem to help).

Love to hear some ideas!

Snarl 12/8 · Post by **Snarl 12/8** » Wed Feb 22, 2012 8:25 pm

Post a clip, or describe, the noise.

sound for sandwiches · Post by **sound for sandwiches** » Wed Feb 22, 2012 8:28 pm

IS it 60hz type noise or something else? did the noise come on strong after being quiet previously, or emerge slowly with time? has the amp been modded or worked on recently?

I can think of a few things- dirty or damaged input jack, bad power supply caps (unlikely in a newish amp) but more info would help.

David

davidhoffmanmusic · Post by **davidhoffmanmusic** » Thu Feb 23, 2012 6:05 am

It's definitely a 60hz-type hum. Only happens when the guitar is plugged in and turned up, so it might very well be noisy pickups - they're from a 70's Les Paul.

vxboogie · Post by **vxboogie** » Thu Feb 23, 2012 6:08 am

More questions:
Has it always been this noisy?
Are you using high gain settings?
Do you have pedals inline?

Jim Williams · Post by **Jim Williams** » Fri Feb 24, 2012 8:53 am

It's the guitar, not the amp. That's why the hum goes away when unplugged.

Dakota · Post by **Dakota** » Fri Feb 24, 2012 9:44 am

davidhoffmanmusic wrote:It's definitely a 60hz-type hum. Only happens when the guitar is plugged in and turned up, so it might very well be noisy pickups - they're from a 70's Les Paul.

That could be symptomatic of the "ground" being improperly connected inside the guitar wiring harness. Ground could be flipped somewhere, left partially hanging, or not connected to all the shield points. 70's les paul humbuckers aren't known for being unusually noisy.

vvv · Post by **vvv** » Fri Feb 24, 2012 1:38 pm

Could be the cord, also.

Try a different guitar, a different cord, make sure no pedals are in-between.

Brian · Post by **Brian** » Sun Feb 26, 2012 1:47 pm

Cord, amp jack, guitar jack, or internal guitar wiring broke loose.
Maybe.

shedshrine · Post by **shedshrine** » Mon Feb 27, 2012 10:06 am

I swapped out a cheap outlet strip for a dedicated effects supply(voodoolabs pedalpower 2) and the hum left on mine.

I didn't get to keep all the pedals though.

mikelevitt · Post by **mikelevitt** » Fri Mar 02, 2012 2:30 pm

Take all of the resistors out of the amp. Resolder them in backwards. That won't do anything, but you will have a few hours of quiet while working on the amp.

Seriously, try a different guitar. A different guitar cord. A different room.

Guitar amps are noisy - they need all of that gain to sound right.

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Troubleshooting a Noisy Guitar Amp

Troubleshooting a Noisy Guitar Amp

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