Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

wkpro

New member
Hey guys-- longtime guest, but finally joined the forum as I need some help. I recently got my first Gibson Les Paul used, and unfortunately there was something funky going on with the pickups/electrical. I decided to replace the entire "guts" and pull out the PCB innards. I went with a StewMac "Golden Age" kit with everything there for a traditional Les Paul setup, plus push/pull for single coil operation (as I've heard great things about the JB and Jazz split).

Long story short, the shop I bought the guitar from offered to install the kit free of charge since the previous electronics had an issue. I have installed some pickups before (SSL-1s in my Strat), but never did a total gut job. I figured, why not have them do it free and not worry about it? However, when I went to pick up the guitar, the tech seemed very confused about the modern/50's wiring differences. I had told him I'd prefer "modern" (it's just what I'm used to), and he said he set it up that way-- but removing the panel reveals something a little different than what I expected for modern wiring.

In the diagram from StewMac, it looks like the MIDDLE lug of the tone pot should be where the capacitor is connected, and that the 3rd/right lug should be soldered back to the pot itself. It would appear, to me, that he has it all set up right regarding the capacitors connections on the volume pots, but that with the tone pots he has left the middle lug soldered to the pot (this is the way the StewMac kit came) and used the 3rd/right lug to connect to the capacitor.

Now I'm a little out of my league here, so when I asked the tech about it he seemed unsure, but he also kind of stuck to his guns and said he thought it sounded fine. I'll admit the pickups DO sound fine to my ears overall-- but it did sort of seem like the volume pots "die off" quick. By which I mean it seems to drop off a ton of volume between like 10-7, and then 6-1 is all very similar/almost silent.

I'll attach some pics for those of you better than I to analyze. I feel relatively confident he did the rest of it "right" but please let me know if you see anything amiss. I can always get better pics if something needs more clarity, as well. Thanks in advance for any help!

EDIT: The black pots are push/pulls on the tones-- so that should help with orientation for the photos. I didn't realize until I posted them that some are "upside down"-- sorry!

IMG_2260.jpgIMG_2261.jpgIMG_2262.jpgIMG_2257.jpgIMG_2258.jpgIMG_2259.jpg
 
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Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

It doesn't matter if the tones are wired with the cap wired to the left or middle lug, they operate the same. The volumes going quiet from 6-0 has to do with the taper of the pot itself - an audio taper. If you want a longer taper you can use linear taper pots, or you can reverse the left and middle lug connections.
 
Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

Thank you so much for the response! So to clarify this in my head a bit, is the difference between 50’s and modern wiring more about where the volume lug connection is made with the cap then? And does the specific tone lug used not matter? Because in the schematic I had, the lugs used on both the volume and the tone pots changed from 50s to modern wiring. If I remember correctly it was:

50s: volume middle lug to tone left lug
Modern: volume right lug to tone middle lug

And to clarify my “right/left” lug definitions, I’m talking as if you were looking at the pots with the lugs straight up.

Sorry if anything I’m asking here is unclear or, worse yet, a dumb question. I’m just learning. I want to do this kind of work myself in the future so I want to know the “why” behind this stuff.
 
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Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

Modern wiring takes the feed to the tone pot at the input to the volume pot, whereas 50s wiring takes it from the output of the volume pot. From the pics, it looks like the tech has connected it to the input of the volume, so it’s Modern wiring.

Where the confusion may be coming from is that most modern wiring schemes run a wire to the tone pot and have both ends of the cap wired to the tone pot. In this example, the cap is acting as that wire and the tone pot simply dumping to ground. I’ve read that either way doesn’t make a difference electronically - and my ears sure aren’t fine-tuned enough to hear the difference!


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Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

Ok, I think I’m getting it. Really appreciate both responses! So one final question: what is the actual difference between the lugs on the tone pots? Are they all functionally the same then? I’ve heard the middle lug referred to as the wiper lug I think? I guess that’s where some of the confusion has come from for me, as well. I had always assumed they each had some separate function, but it seems like you guys are saying the lug the cap is attached to on the tone pot isn’t a significant factor. Is that correct? Again, sorry if I’m exposing how little I know!

You guys are really helping a ton. I plan on studying up on all this more seriously in the future, but right now with two kids under the age of 3 at home, I was just looking for a quick answer so I can enjoy the rare playing time I get!
 
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Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

Ok, I think I’m getting it. Really appreciate both responses! So one final question: what is the actual difference between the lugs on the tone pots? Are they all functionally the same then? I’ve heard the middle lug referred to as the wiper lug I think? I guess that’s where some of the confusion has come from for me, as well. I had always assumed they each had some separate function, but it seems like you guys are saying the lug the cap is attached to on the tone pot isn’t a significant factor. Is that correct? Again, sorry if I’m exposing how little I know!

You guys are really helping a ton. I plan on studying up on all this more seriously in the future, but right now with two kids under the age of 3 at home, I was just looking for a quick answer so I can enjoy the rare playing time I get!

The way I think of it, the two outside lugs are either end of a strip, and the middle lug (the wiper) is connected to a slider on the strip. As it gets closer to either end, it “sees” more of the lug it’s nearest to.

So, if the wiper is connected to ground, as it approaches and outside lug, the more of that lug’s signal is dumped to ground.

The signal doesn’t really care whether it goes:

Volume pot-cap-tone pot-wiper-ground; or

Volume pot-tone pot-wiper-cap-ground

As it’s all about the proportion of signal dumped to ground via the cap (as I understand it).

The difference with 50s wiring is about the treble being removed before or after the volume pot - as any pot reduces treble when it’s turned down, if the tone pot is connected before, then as soon as either pot is engaged, it’s like double-treble-cut.

With 50s wiring, the treble is drained off at the very last point before the signal hits the jack. If both pots are on full, it won’t make a difference (to my ears) - but if either pot is used, it changes the way the the treble disappears.

I have versions of both schema on various guitars - 50s on my Les Paul, modern on my 335 (only because I didn’t want to futz around through the f-hole!), modern with a treble bleed on my Music Man Reflex, 50s wiring with a no load tone pot on my Telecaster - as you can probably tell, it’s whatever sounds best for the particular guitar in question.


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Re: Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

VinceT-- can't thank you enough for that explanation. For the first time, I think I get it from a conceptual standpoint. Who knows, maybe I'll eventually try 50's wiring someday now that it's less of a mystery to me. For now, I'm just happy to know everything seems to be wired up correctly. And honestly the quick taper on those volume pots I mentioned earlier works pretty good for volume swells, so I guess I don't mind it too much as long as nothing is "wrong" with it. I live in a very, very small town and this is a new guitar shop so I was probably a bit more nervous than I needed to be.

I will add this: the JB and Jazz truly are an awesome combo. Definitely more in your face/hot than the Burstbuckers that were in the guitar before, which is what I wanted. I was really pleased with the coil-tapped tones, as well. I'm still going to turn to my Strat when I really need single coils of course, but I love the flexibility. Between these and the SSL-1s in my Strat, I have been very happy with SD.

Thanks again to Clint 55 from earlier, as well. What a great community. Glad I finally joined!
 
Guitar Tech Install of Jazz/JB Combo in Les Paul w/Modern Wiring

You’re most welcome. There’s a lot of language gets thrown around here and other forums that assumes knowledge - so it actually helps me to lay it out for someone else!


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