What I read on forums is that they try to emulate the active EMG's in a passive design, using a ceramic magnet. They sound tight in the bass and overall a bit dry, lacking character and sustain, especially in the upper register.
DC-resistance is somewhere between 8-11 k, depending on the type HZ. RiffRaff is around 8k.
RiffRaff has an alnico V-magnet and is will sound warmer, more vintage and cleans up better. I think you'll be amazed, as with all BKP's I have, how much depth and clarity they have.
Here's the description of the RiffRaff on the BKP-website:
Tight and punchy bass response with a smooth bite in the high-end define the voice of early '60s humbucker-driven rock'n'roll.
The Riff Raff humbucker is based on the shorter rough cast Alnico V PAFs of 1960, with a more symmetrical wind of 42 AWG plain enamel wire providing more focus in the upper-mids and brighter highs. While the same build standard and components of the other vintage humbuckers in the range apply, the Riff Raff delivers a more aggressive vintage tone and unmistakable rock voice. The bottom-end is deep but very controlled and coupled with the extra cut in the high-end, allow for plenty of snap and a classic range of organic, clean and driven tones.
Although voiced as a vintage rock humbucker, hard rock and metal players will enjoy the punchy and focused tone when used with hi-gain rigs.
