Volume loss while playing - pickups?

[Rush]

Figured I would field the question here on the good ol' EB forums. Glad to see this forum still going strong after so many years.

My main guitar has been a 2002 EB Petrucci 6 string (no piezo) since 2006. For the past few years I've experienced intermittent volume drops while playing it. I did all sorts of testing, but it was so elusive it kept me guessing. Sometimes it would show up immediately, other times not at all. At first, I thought it was a bad tube or circuitry in my Zoom G92.tt unit, so I sold that off and bought an NUX MG-30 which is excellent. I run L/R out into two Roland Cube 30 solid state amps via the AUX and use them as monitors.

The volume knobs and pickup selector work fine with no hum or noise when using them. Nothing is loose. The issue showed up earlier this week while playing the NUX, so now I'm confident that it's the pickups or something else in the guitar.

What should I check first?

Signal chain:

1. Guitar
2. Planet Waves Cable (tested, good)
3. NUX MG-30 (brand new, up to date firmware, tested, good)
4. L/R cables out to AUX input of two Roland Cube 30 amps (left / right)

 

[DrKev]

Does the volume disappear completely or just drop a little? Does it happen with just the bridge or neck pickup, or can it happen with both?

 

[Rush]

It just drops in volume and returns when it feels like it. I haven't had an opportunity to see if pickup selection makes a difference during the volume drop. I plan to check that. I want to say it happens with both since I do switch between them frequently.

 

[DrKev]

Also spend some time playing straight into the standard input of one of the Cubes. If you can't reproduce it that way you know it's not the guitar.

 

[beej]

Troubleshooting this stuff can be a real pain. When you have intermittent problems, things can test fine but still be a problem. The key is to gradually eliminate things and try to figure out where the problem is.

As Kev says, figure out if it's just the bridge pickup or both. (Just play the neck pickup for a while and see- then both, then the bridge.) It could be a loose wire in the cavity partially shorting things out, etc.

I'd try a new cable as well- could be a break in the shield, so the cable shorts a bit when bent in a particular direction.

Then plug right into the Cube- eliminate the NUX and the connecting cables.

It's one of these things. Just have to stay on it until you figure out which.