Popping noise in Yamaha TRB6 electronics

[MrWalker]

I have a Yamaha TRB6 from the 90s sometime with the John Patitucci preamp (the one with three presets on the mid tone control instead of a more traditional cut boost control).

However, when I play, there are audible pops, it seems like something is shortcutting the pickups, and it seems to be popping around the pickup screws (maybe this is not correct, but that's how it feels). It's not like a ground noise thing, it's more like "sparks"... as if you touch something carrying current and getting an electric shock (very mild one, I'm not getting electrocuted just yet).

Does anyone have any idea what this can be caused by?

For some strange reason I have a set of Bartolini G6 pickups (7-string but they are the same size as the Yamaha pickups) and I was thinking I could just get a new preamp and replace the entire wiring to get rid of this problem, but just wanted to check out if there was an easy fix to it... cause the bass sounds really lovely except for the pops...

Anyone have any experience or input on the matter? It would be greatly appreciated!

[Ziechn]

I have experienced such a pop.

I have a Fender Jazz Bass and when this happens to me I notice that I'm pressing the E String to hard with my thumb and it touches the Pick-ups, causing a Pop.

I'm not sure if this is what is going on with you, but check it out.

-z

[MrWalker]

Thanks for your rapid input!

No, it's not an issue of pressing the E-string to hard on the pickup. It's not a contact noise, it's more like an electrical shock, and sometimes I even feel it in my fingers. It's as I'm causing a shortcut to occur. It's like the pickups are charged and is discharged through my fingers to the grounded strings...

Could it be a grounding issue? Or a preamp failure?

EDIT: The preamp is pretty weird on this one, it's a gigantic printboard with all the pots soldered directly on the board. The bass took a heavy impact around the area with the pots at some point in time (before I bought it, which the seller never brought to my attention), and apparently one of the pots took a heavy hit. If there's an issue with the preamp, it will be hard to figure out what's wrong, really... given the complex nature of it. In that case I guess I'll just have to replace it with something else.

The reason why I'm asking about the grounding issue is that I've never heard grounding issues that sounds like this...

[canoseti]

I HAVE THE SAME PROBLEM WITH MY TRBJP. AND I DONT KNOW WHAT TO DO.

[Bob C]

I had a similar problem with my Carvin LB70 a long time ago. I would describe my malady as a "snapping" noise. I actually had the preamp replaced, but had issues again later on, which I'm almost certain were caused by static electricity.

I was told to try a dryer fabric sheet or use electronics anti-static spray, but I opted for a plain piece of paper cut to the size of my electonics cavity. And it did the trick! It keeps the static or whatever from building between the electronics and the underside of the plastic cover (on the back of the bass). At least that's my theory.

I have read about similar problems with Fender guitars and basses that have metal pickguards (ie, Marcus Miller Jazz, I believe). My bass has been symptom free in that area for a number of years now.

[MrWalker]

That's a great advice! I'll have to try that out!
Thanks for your response, I'll be sure to report back!

[Bob C]

MrWalker,

I just reread your post. I missed the part about you getting a shock the first time. It's still possible that it's a static problem, but I kind of think it's something in your wiring - especially since you said the preamp was banged around at one time.

I would take it to a repair guy. See if they can trace the current, or whatever. There could be a short somewhere in there. I'm guessing you've already looked under the hood for loose wires, right?

[LowBHighC]

I've been experiencing the same problem with my TRBJP2. And it happens on intermittent occurrences, i couldn't isolate what's causing it.