Back around 1980, I modded my 69 jazz. I put a stereo jack in place of the original mono, then wired the neck pup out of one side, and the bridge pup, through the tone pot, out the other side. I had two identical EVM 15L single 15 custom cabs, a traynor bassmaster, and some old Peavey solid state head.
The neck pup went straight to the Bassmaster, and the bridge pup went through a Little muff, and a Small Stone phase shifter, to the Peavey. It was awesome.
I played it that way for about 6 years, before restoring the original wiring. Made no new holes, and only had to buy a stereo jack.
