Well hello chaps, I thought I'd better say hello and explain Bridgehouse's pickup as I'm the person who designed and wound it :-)
My business involves a hell of a lot of pickup rewinds (as well as building new pickups), and the most common bass pickup to need my ministrations is that 'certain classic California-made' bass we are discussing. It's always had me thinking that it's kinda an object lesson in how to break the mould in bass pickup design ... because it's actually built pretty much the opposite way to the way you'd expect to produce bass tones. It's thin bobbin and super fine wire combined with relatively low output is really poles apart from the tall bobbin, thicker wired P Bass and J Bass. There are plenty of guitar pickups that use the squat bobbin approach: the P90 and the Jazzmaster are two notable ones, and they instantly sound different to taller bobbin pickups like Strat ones. My instant thought was to replicate the tones Bridgehouse was looking for (without tons of extra EQ) a 51 P Bass bobbin was too tall and would accentuate too much treble over mids. So I fired up the laser cutter and produced a custom bobbin of exactly the same winding area as the ... um ... Californian bass, and sat it atop a ceramic magnet ... filling it to 14k with 44awg wire. As a finishing touch I added adjustable dome head steel poles.
Now does it sound exactly like the original?
I popped it briefly into my bass pickup test guitar (a P Bass partscaster with a dirty big central rout) and gave it a little go ... I ended up with a big smile. Not an exact ringer, but a lot closer than I've ever got with a Precision and no EQ.
I'll leave it to Bridgehouse to do some sound samples ... but I'm pleased I proved a bit of a concept, at least to myself.