I've never heard the OB-3 in a bass with single coils, but have lot's of experience with it in various other basses (Drozd, Stambaugh) etc. with split coils or dual coils, etc.
I personally didn't dig it. The low shelving point is very low, and the treble shelving point is super high (like 10k or something). I assume they did that so the bass and treble wouldn't sit on top of the switchable mid when set high or low. It sounded very pure and quite hi fi. I prefer a two band with a big more meat to it myself. It's a quality pre though, pure personal taste.
Thanks for the opinion. Pure and hi fi don't sound to my liking, but the Tone Hammer, which I thought had the OBP-3 in it, seems quite different. The bass is at 40 Hz and the treble is at 4 kHz. That's the same as the Sadowsky right? I got the info from here: [Invalid or Expired Link Removed]