Gibson's PCB and the case for upgrading pots and caps (mirrored post)

[SpinWheelz]

In the past 12 months, I'd picked up two Gibson Les Paul Studios: one a Vintage Mahogany, and the other a rather run-of-the-mill Alpine White. Each of these came with a PCB in the control cavity:


I have since removed the PCB in both my Studios and have upgraded them with RS pots and a variety of PIO caps. If the immediate benefits of RS pots and PIO caps aren't immediately apparent, then consider the pot values I took of the PCB:

PCB 1:
Neck volume: 287K
Neck tone: 447K
Bridge volume: 311K
Bridge tone: 423K

PCB 2:
Neck volume: 322K
Neck tone: 502K
Bridge volume: 349K
Bridge tone: 418K

Most of us would agree that when you're armed with two humbuckers, you typically want 500K pots all around. You'll see from the numbers above that only one comes close 500K. Consider the range in the rest of the pots. PCB of not, the Gibson pots would appear to be "choking" the life from your pickups' potential, no?

That's why I thought I'd try and work out a wiring schematic for re-wiring the PCB. The biggest trick was trying to figure out what wire did what, so I've tried to color-code them almost exactly according to what you'd find in the control cavity.

Please note green does not to green, going into the jack. Green goes to black, and black goes to green. Also, please note the added ground wire going from the ground lug in the jack to the back of a pot - without this, you'll get a massive humming noise no matter what. The black wire from the toggle switch going to back of the bridge volume pot us actually the bare wire with a bit of black heatshrink around it.

Also, I've drawn this up using '50s wiring.

Not sure if this'll be useful to anyone, but I'm such a believer in removing the PCB and upgrading the pots and caps, I felt compelled to share. Please ignore the attached thumbnail at the bottom of this post - I'd inadvertantly attached the wrong file to my initial post.

[FF_Pedals]

Are you sure you don't have the tones and volumes reversed? My 97 Studio had 500k volumes and 300k tones I think.

[SpinWheelz]

Unless I'm using the multimeter incorrectly (entirely possible, since I only picked it up yesterday), I got the same readings when I took the measurements again. My volume pots are registering lower values than the tone pots.

[FF_Pedals]

I bought some Fender 500k CTS pots to "upgrade" my Agile that had import pots that actually measured 500k. The Fender ones read around 430k and I swear the guitar sounds muddier now.

[cynic79]

Originally Posted by FF_Pedals

Are you sure you don't have the tones and volumes reversed? My 97 Studio had 500k volumes and 300k tones I think.

Makes me wonder if they wired the damn thing backwards.

Assuming that they were actually shooting for 300k volume and 500k tone values, the tolerances seem to be within the normal range for most manufacturers. A +/- 20% tolerance isn't unheard of.

[MrRhoads]

Yeah, rip out that "PCB"...
The pots are unbelivable.
I actually emailed Gibson the other week about there bad stock electronics holding the pickups back but they answered with that tone is subjective and is all about personal taste.
Ha ha ha

[SpinWheelz]

Originally Posted by cynic79

Makes me wonder if they wired the damn thing backwards.

Assuming that they were actually shooting for 300k volume and 500k tone values, the tolerances seem to be within the normal range for most manufacturers. A +/- 20% tolerance isn't unheard of.

I'd posted this same thread in the Gibson Les Paul forum, and someone there suggested that 300K volume pots and 500K tone pots come standard on all Standards? That was the first I'd ever heard of it.

[MrRhoads]

Just took a Ohm reading on my old Gibson pots from my Les Paul Standard Faded.
The Volume pots were 220kOhm & 310kOhm
The Tone pots were 473kOhm & 505kOhm
Don´t remeber which were which but this clearly shows that they just take the first pot the find and slam it in the guitar.

I did e-mailed this numbers to Gibson
I´m eagearley awaiting their reply.

[b-squared]

I'd love to see some 'after' pics!

I really dig RS stuff.

BB

[MrRhoads]

Originally Posted by b-squared

I'd love to see some 'after' pics!

I really dig RS stuff.

BB

Yeah, the switch to RS stuff is amazing
It´s really what should be stock in every Gibson.

[MrRhoads]

I bought a RS Superpot 280kOhm the other day.
According to RS Guitarworks they can range between 250-300kOhm and it read 264kOhm.

[Boritch]

Originally Posted by MrRhoads

Yeah, the switch to RS stuff is amazing
It´s really what should be stock in every Gibson.

I agree, if new lps came with the RS guts it would save hours of setup time and $70 bucks. Upgrading stock electronics is like paying taxes, you just have to.

[kernelofwisdom]

I ran into one of my LP's the other day that you have to take the volume down to about 3 before the pot goes active in actually taking down volume. Luckily, I keep an RS emergency kit around to correct this kind of thing.

Some Gibsons have pots that don't taper materially until they are down to 3-4 and some are reasonable. Don't know why.