Had to turn certain wiring upside down. You have to make sure it is not in reverse, otherwise you will either get no sound, or you will get a straight pickup to jack effect, with no control over t he volume or tone. Finally got it wired up, and the sound is great. I replaced the Jazz type pickups in my mid 90's Carvin LB75 with EMG Jazz pickups. The original preamp kept fading in and out, so it was time for that change. I bought the pickups from Sam Ash Music in their old Canoga Park (Los Angeles) store. I bought the BTS from an online seller through eBay called "Don't Tell The Wife". Came with all the necessary parts and wiring. Almost gave up and went to a local sound repair person, (who wanted a lot of money to do a simple wiring thing). Patience prevailed, the wiring is all done, and the instrument is sounding better than before. I recommend pre wiring the setup, just to test everything to make sure it works before installing it. Wiring it all up before installing it is recommended.

Nice video , in fact the web page does not shows to connect the mid range control , even on the 4 knobs option. Thanks for the video.

Wow nice video

Rob, really? I just purchased this preamp, and nothing when schematic followed. How about some tips on troubleshooting?

Hello ¡ does it work for a spector euro 4lt with p j bartolini pickups? Thanks ¡