HUMPBACK ENGINEERING 1x2. This is an onboard preamp. It's a 2-band preamp with bass and treble controls. I had it installed in a Fender Jazz Bass, and it's the "original sound-focused" type that's popular these days, boosting and cutting the original sound directly. If you're looking for a big change, something like a Bartolini might be better. Please see the images for the adjustable frequency bands. The wiring to the pots is as it was when I was using it, with the order being volume, balancer, treble, and bass. I was using it without an on/off switch. I don't have any wiring knowledge, but I think someone who knows about wiring could use it right away with a little work. *See wiring diagram. I had the installation and removal done at a musical instrument store in Tokyo. It was in use until right before, so there are no issues with its operation. Price reduced from 17,000 to 16,500. I will not be lowering the price further. Also, the price is set at this level because the pots are already wired. Thank you for your understanding. #Bass #Preamp #HUMPBACK #HUMPBACK ENGINEERING