Take my 4 stars with a grain of salt, as I didn't check the sizes of the mount holes on my bass.. so I had to rewire mine onto different pots that actually fit my bass. I have changed the tone/response of the preamp a little since I used some separate valued pots, the end result is the active volume being a little quieter than passive mode with everything leveled. A little boost on both the B/T controls fixes it with plenty of room left to move, so it's not a big bother - and I'm almost positive due to my specific rewire anyway.

That being said, sounds great! Purchased as a replacement for my Carvin as I wanted to trade its 3 band preamp for a two band with a tone control instead (wiring in a tone control to this is easy as well!). I still mainly use passive, but this gives a good controllable boost and that sweet Aguilar active sound where i want it. The wiring kit I received was wired up nicely and packaged nicely as well. Plus I got a sticker in the box, hell yeah.

Purchased OBP3 from Fat Bass Tone and on my Warwick thumb bass had to give up active passive knob for concentric knob . Sounded good just couldn’t get used to knob . Called Max and ordered obp2 and now I’m back in business . Max is pleasure do business with I highly recommend Fat bass tone to anyone who wanna upgrade pre amp or pick ups . You can’t go wrong with Fat Bass Tone my new obp2 kicks ass

Installed in my Carvin B4 with Aguilar 60j pickups. Clean quiet sound!!

I have always been a "passive pickup" guy but was looking for a little more top end clarity and bottom boost. I installed this OBP-2 bass preamp in my Waterstone 12 string bass and wow it really woke it up!

To say I had a great experience would be an understatement! I received amazing, friendly and knowledgeable service. My go to guys from now on!