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Question about passive pickups wiring

PostPosted: Thu Aug 18, 2016 12:07 pm
by jim.i
Hi Paul, I did a minor reversible mod on my old JB-2 (and will likely do on my incoming JB): i cut/soldered two leads so that the pickups were wired in serial rather than stock parallel. Neck pickup knob became single volume control for both pickups, bridge pickup knob inactive, tone knob unchanged. The resulting sound was still definitely that bark and growl but now had the big full bottom end that i don't typically hear on passive "J" style basses, and in fact it sounded fuller throughout the frequency range, not just in the lows. Also provided humbucking operation as both pickups were full on.

This seems to me like an obvious "improvement" in sound, like having the advantages of active boost without battery and extra electronics. My question is, do you know why this wiring scheme has not become more common, or even as an option (like a push/pull knob or switch for parallel/serial)? Just curious...
ps it's GREAT to have you here, big thanks to you and Ken for your participation.

Re: Question about passive pickups wiring

PostPosted: Fri Aug 19, 2016 6:47 am
by Paul Gagon
Hi Jim,

First off, thank you for exploring ideas on your bass and sharing them with us. This type of experimentation is what gives rise and life to so many "Features" on musical instruments. To answer your question, I don't know why this isn't an option. Typically, instrument options like this would be implemented when a company's sales and marketing team got requests from dealers, distributors or artists. Personally, I think what you did is excellent. Wiring single coil pickups in series, especially when they are separated by a few inches, can sound incredible. Putting this type of feature on a JB-2 seems like really good idea. Anybody else out there ever try something like this?


Re: Question about passive pickups wiring

PostPosted: Fri Aug 19, 2016 7:26 am
by jim.i
Hi Paul. First, i have to give credit to a couple bass-buddy's and G&L super-fans Brad "bdgotoh" and Todd "tdr1138". Brad suggested this mod to me some time ago when we were both whining about the lack of low-end oomph on typical passive J-style basses. I don't know where Brad learned of this or whether he figured it out himself; maybe he will chime in here. Todd suggested an additional mod, either replacing one vol knob with a push/pull knob pot, or adding a switch, to go between stock parallel and serial (I guess the thought of a useless second vol knob when in serial made his teeth start to hurt). I did not want to add a switch; that would not be reversible if a hole was cut. The inactive knob didn't bother me (sorry Todd).

I did have another builder's J type bass modded to make the neck ie front vol knob push/pull, with the "down" = serial since that is the way i used it 99% of the time. That too was Brad's suggestion, to avoid accidentally pushing the knob down (and going back to parallel) while playing. I should mention (i had forgotten) i did have a Canadian passive bass with crooked frets a few years back and it had a 4-position click knob: neck pup, bridge pup, both pups parallel, both pups serial. I thought that was pretty cool.

As i mentioned earlier, we were both pleasantly surprised to discover the fullness added throughout the full tonal range, not just in the lows. Even better, it was still very obviously a J sound, with the lovely snarl and bite but now very ballsy - and no stinkin battery.

Ken, this discussion is probably verging on "Experimental Bass" page placement, i'll let you decide where to stick it ;)

Re: Question about passive pickups wiring

PostPosted: Fri Aug 19, 2016 8:13 am
by TDR1138
My guess is that people are accustomed to a J bass, so the market accommodates that. (Had Leo designed the thing in series in 1960, would we be asking how come people don't make a bass with the pickups in parallel and with a second volume knob?) It's just the fundamental design of the bass for the last 56 years.

That said, even Fender monkeyed with a series/parallel switch on the Jazz bass from 2004 - 2008 in the form of the "S-1" switch. I think the Jazz is one of the only instruments that it went on where people actually felt it was beneficial (it went on Strats, Teles and P basses, too). Plus I think they had some issues with the switch. It's a push-button on the front volume knob, but if you opened it up, it looks like some wacky rotary switch with a ton of terminals, which I think made things prone to failure and more complex than they needed to be.

My main thought in suggesting a push-pull or mini-toggle to switch between the two was just for versatility, really. You can still get that "Jazz" tone if you want it, or you could flip it into series and make it sound good. :P

Re: Question about passive pickups wiring

PostPosted: Fri Aug 19, 2016 9:04 am
by Ken Baker
jim.i wrote:Ken, this discussion is probably verging on "Experimental Bass" page placement, i'll let you decide where to stick it ;)

Nope - it's fine right here.

Paul Technicalities is a great place to discuss design aspects and ideas about mods & experiments with G&L basses, and of course the electronics of the beasts.

Chat it up, folks! I think this is great.


Re: Question about passive pickups wiring

PostPosted: Fri Aug 19, 2016 9:35 am
by Paul Gagon
I agree with Ken. This is a great place to explore and chat. You guys are all so amazing and have done so much experimenting and diagnostics on G&L basses. I really wish I had been more plugged in to all of you during my employment at G&L. It would have been much easier to help you with drawings and different pickup ideas and such.

Modifying basses is a ton of fun and there are soooooo many things that can be played with. I know the thought of adding mult-position rotary switches to a bass really freaks some people out but it can be quite educational and let you try things out on the fly. Not every option is gold but if I've learned anything in my life while modifying guitars, basses, effects pedals,...sounds that one person might hate is many times another players "Main Tone". Everything deserves a try.

Thank you for pushing the boundaries and sharing what you've learned. You guys are the best.