I've just installed (piece of cake) a J-retro preamp in my MIA Fender Jazz Deluxe V, and I just want to tell you, this baby is the s**t! Way, way better than the Fender preamp. Fat, punchy lows that get lower as you increase the boost. Sweet treble that cuts the high mids (1khz) as you boost, and a pull function that boosts extra high. Sweepable mid-range that enables you to go from James Jamerson to Jaco (although it does'nt make me play as good as them) Active/passive switch. Can you tell that I like it? BTW; I got mine from the Dude, Steve Barr, and I wholeheartedly recommend him to anyone wanting to buy mailorder.