Music Man Stingray Preamp Faulty?

[Gerry Hayes Haze Guitars]

Hi Nicola

My active electronics knowledge isn’t strong enough to help you track down a faulty component on the preamp board. Sorry. A couple of things worth checking though.

First is to check or even replace the battery clip. Because it’s handled and pulled around a lot, these fail pretty easily. I’ve found more than a few preamp problems that were down to loose or troublesome connections on the battery clip.

Related, check the 9V connections on the board to ensure, it’s actually getting power when the jack is plugged in. I suspect this isn’t the issue because you’re hearing some noise but it’s worth checking.

If it’s neither of those (off board) things it looks like being a preamp component and things get more difficult (for me, anyway). Is the noise you hear consistent? Does it change if you adjust any controls? Does moving or (carefully) tapping the board with something non-conductive cause any change? Same question for any pickup, battery, or jack hook-up wires. Can you hear a clunk if you tap a pickup pole with a screwdriver? Is the noise random or repeating?

[Nicola Casadei]

Hi Gerry, thanks for your reply. First thing I did was to try a different batteries then I changed the 9V connector and the noise is constant when the battery is plugged in. No noise coming from the pickup but just a constant buzz. If I unplug the battery I get sound from pickup and the bass plays as passive and only the volume pot works. It seems like a component problem. The owner used regular WD40 on pots and I think it messed up the situation. I’m gonna try to resold every connection on the board with the pots to see if something change

[Nicola Casadei]

The problem seems on the IC that got faulty with regular WD40 used by the bass owner, I passed the ball to another tech who works on preamp and other electronics. I’ll keep you updated

[Gerry Hayes Haze Guitars]

Hope it works out. 👍