Originally Posted by lonote
I have been trying to get a preamp from G & L for more than a year. I have been going through a local G & L dealer. I have actually heard him dealing with the G & L rep several times. I bought the bass with a non-functional preamp, so I don't have any problems with the seller or anything like that, just an unresponsive manufacturer. Does anybody know of a similar sounding preamp that is compatible with the Tribby?
Unfortunately the Tribby preamp is a special design which is unlike most common preamps. It only has high boost. The tone controls are passive and not part of the preamp!
If you've still got the old preamp the answer is not to try to deal with G&L (unresponsive is what they do best) but simply fix the old one. I've had to fix a couple of mine. The usual problem is that the integrated op amp (bug) gets blown. A new one is only a couple dollars. But it's usually not a totally straight-forward job, but any tech experienced with circuit board repair can do it.
Here's the deal. Usually the "bug" is soldered in directly to the circuit board. Removing it and installing a new one takes some skill to keep from damaging the board! It takes a solder sucker and controlled temp solder station and the rest if possible. Too much heat can lift the copper off the circuit board making problems! This is NOT a job for an electronics noob. But, for an experienced tech it's not some huge nightmare either. And I strongly suggest the tech install an IC socket once the old IC is removed so this whole operation won't have to be repeated the next time it dies.
But wait, there's more. The IC in your bass, unless it is rather new, is probably the original one from the design. Those are now discontinued! You can't buy them. But cheer up there are replacement numbers that are actually BETTER than the original. They are cheap and readily available from places like Mouser. And I don't remember the new numbers, but if you dig around TB I'm sure that information is in one of the G&L threads in the electronics forum. Or maybe somebody remembers here off the top of his head.
And of course it IS possible that the some other part (cap etc.) went bad in the preamp, which is actually a pretty easy fix compared to the IC, but the hard part is figuring out WHICH part is the bad one. Again an experienced electronics tech should be able to do this.