I recently ended up with a set of passive EMG pickups and figured I would drop them into my MIM Jazz bass.
What a mess THAT turned out to be!
First a little history. I got the jazz bass in a trade for some other gear. The guy told me it had been fitted with an active onboard EQ. It had a volume, blend, and stacked bass/treble knob and sounded good. No visible battery compartment on the body. I asked and he said it was under the pickguard.
Imagine my surprise when I pulled the pickguard off! It appeared that someone started off with a Dremel, then gave up and went right to the chisel! Yeah, it fits. But man is it ugly!
So then I get to the EQ. No real indication as to who made it. No proper brand name anywhere to be found. But, there is a circuit card that has "www.sho-music.com" printed on it.
The link leads to some Japanese singer's website. So no joy there. I tried the standard Google searches. No luck.
I went ahead with the EMG install and it all sounds good. However, I still have no idea who made it.