Mmm, well, that turned out to be harder than I thought! I managed to find a used EMG SJCSX Pickup for a good price, so fitted that last night, instead of the passive Bartolini. I tried out a few different pickup configurations, but didn't really find anything that works well...
When I tried just the neck EMG and the bridge MEC, it sounded Ok, but the neck pickup was too overpowering. Unfortunately, the pickup route isn't very deep, so I can't wind the EMG down further to balance out the sound. I guess I could either get the pickup route deepened, or fit some sort of gain reduction circuit, but either option is a lot more time and money.
So then I tried all 3 pickups, with the 2 MEC pickups connected as parallel bridge pickups:
1. The neck pickup sounds good on it's own - a strong P-bass type of sound.
2. When the MEC pre-amp is panned to center, there's a distinct loss of output, implying that the pickups are out of phase, or maybe the MEC just can't handle the combined impedance load of the 3 pickups. (Might need an active buffer module.)
3. As expected, the double-bridge pickups sound good on their own, just the same as a stock Thumb 5 BO.
So, I guess I learnt a few more things, but it's still not finished and I really wouldn't recommend anyone modding their Thumb bass in a similar fashion. (Just buy a Streamer as well!)
What will I try next? I might try flipping the ground/hot on the EMG pickup and see if it was a phase issue. But if not, maybe revert the MEC wiring back to standard and wire the EMG pickup direct to the output jack, but with the switch acting as an On/Off switch...
Cheers,
EG
