Below are two of my basses that I've modified greatly. The first is a G&L SB-2, which comes without a tone control (or used to, anyway). I modified it to use only a single volume control which is also a push/pull switch so I can run the pickups in parallel or series with one another. Once I established that I liked that arrangement, I had a new pickguard made for it. The second is a radically modded NS Design WAV4. It started its life as an active bass. I converted it to passive by stripping all the marginal-sounding electronics out of it, putting in a Lace Alumibar pickup (no affiliation), and simply using a volume control only. I have GHS Pressurewound strings on both basses, and both sound amazing. (Please forgive the oddly-sized pics.) Is there anybody else out there brave enough to go volume-only?