Got this to my hands as I’ve been dealing with guitar electronics quite much. Therefore friends and people connected to them are bringing me instruments to fix. I’m pleased to do such jobs, because it gives me a possiblity to test different instruments. After all, guitar electronics is quite simple thing to understand. Anyone could learn to do such jobs, with just a basic knowledge of electronics.
However, owner wanted to add some boost to existing electronics, and had an idea of adding EHX’s LBP-1 inside the guitar. At first it sounded a bit odd to me, but on the other hand, why not? This guitar already had active electronics, but not active pickups. Instead, there was a active hum-cancelling system, which they call ”Music Man Silent Circuit”. I didn’t want to mess up too much with the existing electronics, as this beauty is worth of over 2000 euros.
The plan was as following:
Push-pull -potentiometer already existed, as someone had added a possibility to split the bridge humbucker. That possibility was removed, and push-pull was used to switch between straight and boosted signal. With pot down the signal bypasses LBP-1 -circuit. Stereo jack takes care of cutting the power when guitar plug is not connected. I squeezed LBP’s circuit to minimum and soldered it to tagboard. Finally I placed it to the bottom of the electronics cavity:
The circuit was equipped with trimmer to adjust the amount of boosted signal. All the connections were equipped with quick-couplings to preserve possibility to remove whole the pickguard from guitar if needed. I don’t know if that is very relevant, but the original electronics had this possibility, so I followed the line. With all the electronics put in place there is a hellish traffic rush under the hood:
As a result, the whole system works like charm. Totally interference free thanks to the silent circuit system, even with the boost turned on. LBP-1’s circuit is maybe not the most transparent booster, but surely it is one of the simpliest and least current drawing.
The guitar looks just like it was all original, and it could be easily returned to its original state.