I think most of us here in this forum have seen and been inspired by the Chunger SX mod megathread. I know I certainly was.
That lead me to "chungerize" some of my SX Jazz collection. This included not only the standard shielding, threaded inserts for neck, fret work, pickup setup and damping (foam underneath) but also went further in that I added inserts for pickguard and control plate, for the pickup mounting screws (the Phillips wood screws tend to strip out of the wood as well as get the heads all buggered up if you adjust them much at all) Socket head allen screws for all! And while I was at it I went for new pickguards as well to get rid of that "cheap" white or black look. The effect on the basses was literally amazing!
But there is more. My pet peeve with passive Jazz basses is the vol/vol/tone wiring. It irritates me to try to adjust volume with TWO knobs while playing and attempting to keep the tonal characteristics constant. And in addition, I am VERY MUCH a fan of the series pickup option. For this reason I always modify my Vol/Vol basses by making the first volume control a master volume and changing the second volume control for a rotary switch that selects neck/both series/both parallel/bridge pickups. Works VERY well for me even though you lose a fine adjustment on blending from one pickup to the other. Some of my SX basses now have this mod.
Which brings up version two! "Chungerizing" and the amazing change in the bass tonality, got me to wondering if there was some other way to incorporate series and parallel wiring, but retain a master volume with a "blend" control. Tone would retain it's usual function. Chunger did one bass with "push-pull" switches on all the knobs and I started thinking along those lines. I tried several schemes but all seems to have problems. Either the series didn't work right or the parallel didn't. Finally I developed the following circuit:
http://www.mrk-inc.com/users/fjacoby/SXmodsBlend.bmp
It's not perfect either. When in series mode the "blend" control is not particularly effective, acting more like a switch from one, to both, to the other. BUT, nevertheless is is HIGHLY usable. It gives you master volume and blend which work as you'd like in parallel mode (switch pushed in) and a similar function in the deeper sounding parallel mode with switch pulled out though blend is rather fast acting and only works well at the ends of rotation of the blend knob. But it works well enough that several of my SX Jazz basses have been converted this way. The detent on the Stew-mac blend pot makes a "both" selection a snap in either series or parallel mode. The Speced blend pot is special in that in the "both" position each pickup is on full.
So what about the OLP, I hear you cry! Well, the deal is this: in reworking my SX collection I began to think about the OLP 5 string I picked up fro $100 at GC a while back. It's passive and while a beautiful bass (flamed maple top!) The vol/vol wiring has always been a nightmare. The knobs VERY much interact with each other making it a chore to "dial-in" and the volumes even seemed to interact with the tone control! Feh!
So Inspired by the SX basses I began "Chungerizing" the OLP. I added threaded inserts in the neck and for the pickguard and pickup. I added copper shielding. I properly mounted the pickup to eliminate microphonics. And that's when I decided to try my vol/blend Jazz circuit on it. The main difference of course is that instead of a bridge/neck pickup set the OLP is a Stingray copy with a single twin coil Bridge or near-bridge pickup. So you wire the coil nearest the bridge where the "bridge" pickup goes and the other coil as the "neck" pickup.
The result was AMAZING! Nasty interactions of knobs are virtually gone. The tonal range you can get out of this passive setup are amazing and of course with a decent preamp or the knobs on your amp you can get the further EQ of a "real" stingray. The tone is stingray tone. You think it's going to sound like the Jazz basses the circuit came from, but it doesn't. That OLP now has the unique Stingray thing going that makes that bass so unique in the world of bass guitars. And you can get it without a lot of knob fiddling like I had to do before (which is why I didn't use it much).
I LOVE THIS THING!
PS. wiring with Teflon insulated hookup wire is a plus if you can find some (my mother got mine as scrap where she worked). Unlike normal hookup wire it doesn't melt all over the place when you solder it.
