Microphonic noise coming from guitar won't go away. Ideas?

The Boogie Board

Help Support The Boogie Board:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Audiokill

Well-known member
Joined
Nov 30, 2012
Messages
72
Reaction score
0
Location
Santa Clarita, California
I recently bought a 1984 Gibson Flying V (sans pickguard) off of eBay. The Dirty Fingers in it were beyond microphonic and were swapped out for an EMG 81/60 set. However, the microphonic-like noise persisted, though not as severe with the EMGs. Nevertheless, the noise is so bad that it can even be heard in the form of short whistles between notes while playing. Very annoying. It literally sounds like Herbert the Pervert from Family Guy whistling through the gaps in his teeth whenever he talks.

The noise is a loud, high-pitched microphonic whistle/moan that increases in intensity as volume and/or gain is increased. Proximity to the speakers is a factor in the intensity, as well, but I really need to be about 15-20 feet away with the guitar for the noise to be reasonably controllable. The noise is worst when the bridge pickup is selected and occurs only when the amp is on the dirty/lead channel. Muting all the strings generally stops the noise most of the time. Unplugging the guitar or fully turning down the guitar's volume always stops the noise. The sensitivity of the noise does vary somewhat between different amps. My Triaxis/2:90 makes a lot of noise with this guitar (I generally use lead 2 yellow). Mark III is also a bit noisy. The C+ isn't quite as bad. FYI, I use no pedals or effects. I should note that my gain levels are really quite modest. For example, the Triaxis's gain is only set to 6.0 and drive is at 3.0 ...much lower settings than most metal guitarists use. Volume is basically only loud enough to be heard along side drums and cut through the mix.

Thus began my, as of yet, fruitless search for a cure. Below is a list of attempts to diagnose/remedy the problem;

- Checked my wiring inside the guitar, including any possible grounding issues. All good.
- Applied shielding tape to the inside of the guitar's control compartment. Did nothing.
- Swapped out bridge pickup's only potentiometer (volume). Did nothing.
- Swapped out bridge pickup with another EMG 81 known to be good. Nothing.
- Swapped out tubes in the Triaxis with ones known to be good. No difference.
- Tried using a different cab. Same ****.
- Tried using different preamp and power sections with the Triaxis and 2:90. More of the same.
- Tried lowering Triaxis's gain and drive just to see what would happen. Noise reduces somewhat, but anything higher than 1.0 fails to remove the noise completely.

Things I haven't tried yet;
- Replacing pickup suspension springs with rubber ones. I'm skeptical this will work, though.
- Replacing bridge, selector switch, all wiring. Because I'm out of ideas.

I've pretty much narrowed down the culprit to this particular guitar. For some reason, the strings are interacting with the bridge pickup and the speakers in an overly sensitive manner. Leaving even one string unmuted for a brief moment results in instant feedback. Other guitars with the same pickups and construction being played through the same amp yield much quieter results, including my 1984 Gibson Explorer; same guitar in every way except the shape of the body. Normally, I'd just say screw it and put the **** thing back up on eBay, but aside from the noise, its tone is really, really good. This Flying V is definitely one of my top two axes in terms of achieving "that sound in my head." Plus, it's a **** cool looking guitar. I can't give up on her. Does anybody have any ideas?
 
How does it sound unplugged? I had a guitar with a tremolo where the springs rattled enough to give it a spring reverb sound. I changed the block to a heavy brass one and that fixed it so well I bought another one for my main guitar. I'd check the ground, not just the solder joints, but the wire too, that could cause the noise.
 
The guitar sounds quite good, acoustically. A little bit of ringing occurs from the strings between the nut and tuners on the headstock, but I placed some electrical tape across them to hush any ringing while playing. There is also some slight ringing of the strings between the bridge and hard stop tail piece. I placed electrical tape across there, as well.

I'll check out the grounding wires again, though.
 
Try this. When its feed backing, put your finger on the pup and push down on it without touching the strings. if the noise goes away or is reduced then the pup is too loose in the guitar cavity. Try stuffing some foam underneath the pup and see what happens. This is a common problem with active pups. Also the rubber pup springs will help too.....been there done that. Also try using only one ground instead of a bunch of grounds ie. gather all your grounds together and run one ground wire to the jack. Good luck
 
I had previously tried the push down thing on the pickup. Didn't work for me. Also, I had the ground wire wired up as you describe.

Tried something today, though, and I actually got rid of the noise...somehow. After numerous fails, I was like, screw it, and just removed as much from the circuit as possible to reduce variables. So the entire circuit was changed to only consist of the bridge pickup ---> new volume pot ---> 1/4" jack. And a battery, of course. No neck pickup or anything else was left connected. Used all new wires, too. Also swapped out the existing Tonepros bridge for another one I had laying around that is authentic to the model and year of this V. After making all these changes at once, this thing sounds fantastic now. Eventually, I gotta go back and start adding parts back into the circuit to find the culprit. Probably something stupid like a bad wire, but who knows at this point. I'm just happy I was finally able to save that guitar.

All the input was much appreciated. Thanks guys. I'll post my findings.
 
maybe change capacitor values on volume/tone pots? or maybe someone changed the vol/tone pots to lower values (like from 500 to 250K?). just sayin'
 
Using 25k pots. Put them in there myself. Active pickups are essentially married to 25k.

Finished wiring up the rest of the guitar. The noise is still gone. Guitar sounds great. Still not sure what the culprit could have been. I replaced the first set of 25k pots and all the wiring at the same time. May have been a bad pot or the two cloth-insulated wires I previously had in there.
 

Latest posts

Back
Top