I Use it with fretless Bacchus Handmade series Jazz Bass with ebony, polyurethane flooded fingerboard.
PRE STORY. So, I had very cool passive bass that sounds great in bass amp. But sometimes, especially at home, i playing in line, or directly in guitar power amp without preamp. Because of the high output impedance of passive pickups, treble was sounds friable and not convincing. And i decided to get some onboard preamp. There was no good preamps for my purpose in Moscow. I searched some solution and found it on Thomann. Good price, the manufacturer and the reviews argues that there is "no difference between active and passive mode" and it's suitable for standard JB pickguard. Two weeks and this device was in my hands.
REVIEWE. Installation is veri simple if you have basic skills with a soldering iron. Good, simple and informative manual was includeded. Minimal size: if you have active bass this device plugs whithout problems. Passive may require additional milling for the battery. Manufacturing quality is wery well: plates is reliable, capacitors - WIMA, potentiometer - MEC. So, as i ensured, difference between active and passive mode is really very small. No boost, no specific voice of preamp - and it's what i need. That's sound of my instrument, and I can get it anywhere with same temper. In addition to low output impedance I got an opportunity to active tone control. So, it's very cool stuff - useful frequencys (40Hz & 18kHz) of bass/treble cut/boost makes good tone in all positions of control knobs, without empty or slicing ears sounds.
TOTAL. Good price, good quality, good sound (if you need natural sound of your instrument with additional features).
P.S. Sorry for my English.
