My OLP 5-string originally came wired with a vol-vol-tone setup, but would tend to hum if the two volume knobs were not set at exactly the same level. This was generally tricky to do, so I pretty much always had them both fully on or fully off. I decided to rewire the bass with a single volume and tone, and use a mini-toggle for parallel / split wiring on the humbucker. I ordered a DPDT switch (it was a pack on 5 on eBay), some cloth-covered push-back wire, and they arrived a couple days ago. While I was at it, I decided to get some copper foil to do a full shielding job. The soldering in the bass is pretty bad... I'm not very good at soldering myself, but I don't do it very often and certainly not for a living, but I think the wiring is neater now than it was, in spite of the added wires required for the switching. I quite like the new look - I replaced the middle pot, so it now has the two knobs on the "outside", with the mini-toggle between them. Plugging in, I found out that the cheap pickup in the OLP had incorrect colour coding, so I was getting phase-cancellation. Switched the wires around, no problem. End result - the bass sounds much better than it did! In parallel mode, it sounds just like it did before, except now I have full control over the volume without fumbling or hum. The series mode has a little more volume and has a nice midrangey quality which works well for fingerstyle. I think everyone who owns one of these OLP passive basses should consider this mod... it costs practically nothing and makes the bass much, much more versatile!