guilar DB 924 Preamp, used w/ original box. $100 About 1 year old, heavy use, scratches, knobs have lossened slightly but is perfectly functional, this thing is built in rugged steel enclosure. The DB 924 FET preamp features the circuitry of the innovative OBP-1 onboard preamp in a sturdy and compact package. The sound is transparent and warm and has true dynamic headroom. The DB 924 offers two bands of boost occuring at 40Hz (bass) and 4Khz (treble). In addition, high end loss resulting from long cable runs is eliminated through a well buffered design which provides a low output impedance. Personal testimony: Let me just say that this pre is amazing, i'm only selling because i've upgraded to an Aguilar 659 preamp. Given the cost and ease of use, it's a great yet cheap way to warm up your sound while tightening the low end at the same time. I don't know why it works, but just sending your sound throught this box really makes a difference. I first discovered this while checking rows of high end basses at a music store, and i kept coming back to three in particular. The salesmen was grinning like mad because i had unknowingly picked out the basses with this same preamp onboard. Needless to say, i bought this version so i could use it with all of my basses all of the time.