I've played blues, pop, R&B (60s motown), and rock. I've grown to prefer basses and amps with classic warm tones and pleasing high-end. As such, I like vintage Fender tone through an Ampeg SVT (a real one - tubes).
Since I can't afford a pre-CBS Fender bass, I play a newer G&L L-2500 or a '79 Musicman Sabre (both dual humbuckers, which I like) through a '72 SVT head with new SVT 412 cabs. But lugging my kids college fund around (the SVT) isn't always fun and what I call tone and warmth the lead singer often thinks is muddy distorsion. So, I've looked for a pre-amp to go in front of a Carvin DCM-600 amp to power one of the SVT412's.
After much searching, going cheap (Zoom) to moderately expensive (SansAmp Bass Driver) to weird (microphone tube pre) and playing other solid state amps, I finally took the advice of this page and found a PB-1. I simply can't believe this thing. I seem to be able to tune in my bass to any room and the full parametric that I thought I'd never use is now indespensible (is this where Yamaha pulled the Nathan East EQ?) - totally different and more usefull than the semi-parametric on the SVT, as it has a true Q control. It kicks the SansAmp cold and it seems to be bullet proof as was much of the gear from Yamaha in the '80s.
In any regard, if you can find one that's in working condition at a reasonable price, buy it. I'm sure if you had the time and money to investigate new Ampegs a BBE or Aguilar (or some boutique thing), etc., that would be great as well but that's beyond my patience and means -and I sure didn't like the SansAmp.
Finally, my rig is usually the G&L => EBS multicomp => PB-1 => Carvin DCM-600 => Ampeg SVT-412 and it sure seems to work for me.