High pitch feedback from bridge pickup with tone on.

[jjudas]

My 2020 Epiphone Firebird started acting crazy yesterday. Piercing high pitched feedback when I play on the bridge pickup with the the tone knob turned on. It's never done this before. It's virtually unplayable in that position in this state. Any ideas?

 

[chilipeppermaniac]

I know this is a shot in the dark, but can you turn the knob back and forth a bunch of times and see what it does?

 

[Clockworkmike]

My 2020 Epiphone Firebird started acting crazy yesterday. Piercing high pitched feedback when I play on the bridge pickup with the the tone knob turned on. It's never done this before. It's virtually unplayable in that position in this state. Any ideas?

So its only doing it on the bridge pickup and not the neck as well? Does it do it when your hand is rested upon the bridge still? Sounds like it MIGHT be a grounding issue, possibly the bridge ground connection is weak

 

[LiveeviL2000]

Open the back panel and check the wiring. Move them slightly to see if the noise changes or disappears.
Sometimes wires can shift slightly.

 

[Inspector #20]

My 2020 Epiphone Firebird started acting crazy yesterday. Piercing high pitched feedback when I play on the bridge pickup with the the tone knob turned on. It's never done this before. It's virtually unplayable in that position in this state. Any ideas?

I've had pickups go microphonic for no apparent reason. Have you tried other guitars and amps to isolate this?

 

[smitty_p]

My 2020 Epiphone Firebird started acting crazy yesterday. Piercing high pitched feedback when I play on the bridge pickup with the the tone knob turned on. It's never done this before. It's virtually unplayable in that position in this state. Any ideas?

Does it do this only when playing loudly or at all times?

 

[smitty_p]

I've had pickups go microphonic for no apparent reason. Have you tried other guitars and amps to isolate this?

Yeah, I’m thinking microphonic pickup, too.

 

[chilipeppermaniac]

Did you buy the guitar new?

Let Gib warranty fix it if so.

 

[Inspector #20]

Yeah, I’m thinking microphonic pickup, too.

According to the Epiphone website, your guitar is equipped with the ProBucker™ FB720 pickups and the site identifies them as being wax potted. Of course, you can still get microphonics.

 

[Inspector #20]

@jjudas - Where you located????

 

[smitty_p]

According to the Epiphone website, your guitar is equipped with the ProBucker™ FB720 pickups and the site identifies them as being wax potted. Of course, you can still get microphonics.

Potted? Hmm…that does change things a bit. But, I agree, microphonics are still possible, particularly if the potting didn’t thoroughly saturate the windings.

 

[Inspector #20]

Let's confirm the sub-model of Firebird he has...

 

[iblive]

My initial thought was wiring as well. Bad solder joint on a ground? Pup acting up is also a thought for sure. Had the neck pup on my Strat work one day. A few day later nothing. Got out ohm meter and bridge and middle both had continuity. Neck pup was dead.

 

[jjudas]

Well I read the responses and realized that I didn't do my usual checking before asking for help so I went back and check it out further. After plugging it in i discovered that it was noisy when my hand touched the bridge or near the strings so I took the back covet off. While moving wires around and moving the cap, I discovered the output jack was loose. I'm not sure what fixed it but the noise is gone. Thanks for your help everyone! I appreciate it!

 

[Amp Mad Scientist]

My 2020 Epiphone Firebird started acting crazy yesterday. Piercing high pitched feedback when I play on the bridge pickup with the the tone knob turned on. It's never done this before. It's virtually unplayable in that position in this state. Any ideas?

If it's a tube amp, there can be a microphonic preamp tube.
It's usually the tube closest to the input jack.
turn up the volume, Tap on the tubes and see if any of them are ringing, it happens.
Power tubes can also get microphonic.

What happens with a different guitar?

Effects pedals if used; The setting of the pedals might have changed.
Do you still get the ringing with effects removed?

But what it is caused by is a resonant frequency that can usually be stopped in one way or another....
Notching out the resonant frequency with an EQ is the pro sound type approach.

 

[smitty_p]

Well I read the responses and realized that I didn't do my usual checking before asking for help so I went back and check it out further. After plugging it in i discovered that it was noisy when my hand touched the bridge or near the strings so I took the back covet off. While moving wires around and moving the cap, I discovered the output jack was loose. I'm not sure what fixed it but the noise is gone. Thanks for your help everyone! I appreciate it!

Sounds good!

 

[jjudas]

If it's a tube amp, there can be a microphonic preamp tube.
It's usually the tube closest to the input jack.
turn up the volume, Tap on the tubes and see if any of them are ringing, it happens.
Power tubes can also get microphonic.

What happens with a different guitar?

Effects pedals if used; The setting of the pedals might have changed.
Do you still get the ringing with effects removed?

But what it is caused by is a resonant frequency that can usually be stopped in one way or another....
Notching out the resonant frequency with an EQ is the pro sound type approach.

I use a solid state Randall RG80. I doesn't happen with different guitars. I use a lot of effects but it happened playing clean with a compressor. I also have a 10 band EQ on my board if necessary but it's quiet.

 

[chilipeppermaniac]

If it's a tube amp, there can be a microphonic preamp tube.
It's usually the tube closest to the input jack.
turn up the volume, Tap on the tubes and see if any of them are ringing, it happens.
Power tubes can also get microphonic.

What happens with a different guitar?

Effects pedals if used; The setting of the pedals might have changed.
Do you still get the ringing with effects removed?

But what it is caused by is a resonant frequency that can usually be stopped in one way or another....
Notching out the resonant frequency with an EQ is the pro sound type approach.

I was thinking along these lines too AMS

 

[Clockworkmike]

Well I read the responses and realized that I didn't do my usual checking before asking for help so I went back and check it out further. After plugging it in i discovered that it was noisy when my hand touched the bridge or near the strings so I took the back covet off. While moving wires around and moving the cap, I discovered the output jack was loose. I'm not sure what fixed it but the noise is gone. Thanks for your help everyone! I appreciate it!

All that matters my friend! Glad you're back up and running!

 

[chilipeppermaniac]

All that matters my friend! Glad you're back up and running!

Make sure your Jack's nut is tight. Then before putting the cover back on, make sure nothing in the wiring or metal contacts.wires etc of the jack are touching where they shouldn't.