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Modifications for Gibson and Gibson style guitars Here are some mods for Gibson type guitars. I typically use Les Paul's and SG's, but the setup electrically is pretty much the same. General Gibson Electrical Setup: I'm usually in search of vintage tone with some dirty to it for Blues, Blues Rock, and Classic Rock. I'm of the opinion that Gibson humbuckers need to be 500k ohms (Ώ) with a linear taper for volume and an audio taper for tone pots. I typically use the same cap values as stock, if not the stock caps themselves. At some point (70's/80's maybe?), Gibson changed to pots whose values are anywhere from 250k to 400k ohms (Ώ) on new guitars. I've measured these values myself, but I don't know what their nominal values are, possibly 300k I guess, but I've seen a lot of variation. The lower values darken the tone and a cheap and relatively easy way to unlock the vintage tones in your Gibson is to change the pots. Basic Gibson Wiring Setup 1: Here's a PDF drawing from Lace Music on a typical Gibson setup. I found this very useful. Basic Gibson Wiring Setup 2: Here's another PDF drawing from Lace Music on a typical Gibson setup. Coil Tapping Stock Humbuckers: So you've got a cool guitar with a humbucker or two and you want to do some coil tapping with a switch. You open the control cavity and are stumped when you see that your humbuckers only have two conductors. Check out this page that shows you how to add a new harness that will allow you to do your custom wiring. I have actually done this mod myself and yes I've ruined a humbucker while doing it. Oddly enough I did two and once and thought I was careful with both of them. In the end, one worked like a dream, and one was a paperweight. While not for the faint of heart, this mod is very educational and rewarding. Humbucker Bar Magnet Changeout: Here's a good article on how to change out a humbuckers base plate magnet. While also not for the faint of heart, this mod isn't really that complicated, but you have to have a little confidence to do it. It would help with this one if you had taken apart a humbucker before. Modern vs. 50's Wiring: Some folks like to move the caps in their control cavity around to match the supposedly used "50's Wiring" scheme. They say that this will help keep the tone clear and mud free when you roll down the volume. I've read a fair bit about it and there are some who think it's hogwash, but there are a lot who think it's great. It may seem that it's a trivial change, but apparently the meat of the mod comes from the location of the cap with respect to the hot output of the pickup. The tone pot is basically an "escape" for some of the signal. By turning down the pot, you reduce the resistance of the pot, which "opens" a path to ground from the circuit through the cap. With the modern wiring, the frequencies that are allowed to go to ground don't go through the volume pot so they're lost immediately. With the 50s style wiring, these frequencies are bled off after the volume pot. Here's an image.
Independent Volume Pots: I found this mod online as well. It is indeed a method to do a true pickup blend so that when you roll one volume down to zero, you'll be left with the other pickup where its volume is set, thus the "independent" title. It's cool, but I found that it took some getting used to and I craved the setup that I knew so I undid this one after some time. Here's a drawing.
The "Peter Green" mod: I stumbled across this mod online and was intrigued. Basically, follow the instructions above for changing out a humbucker's base magnet on your neck pickup, but instead of putting a different magnet in, you put the same one back in flipped around. Note that it should be flipped "around" not "over". I don't know a ton about Peter Green or his tones, but I do know that Jimmy Page uses an out of phase tone a lot and I think he was even quoted as referring to it once as "that Peter Green tone". What this mod does is this: by swapping the magnet's polarity with respect to the coil, the neck and bridge pickups are now magnetically out of phase with each other. You won't notice any difference in tone with the neck pickup alone, but the tone is kind of a cool honk when both pickups are on and their individual volumes are at the same level. (For a definition and some electrical jargon on what "out of phase" means, check out www.guitarnuts.com or do a google and you'll find masses of information....) It should also be noted that both pickups can be on but you can quickly adjust either of the volume controls to go back to a more traditional tone rather than the out of phase honk. Anyway, I did this mod and at first I thought that I would reverse it back to stock and fake this mod with a DPDT push/push switch. This would use an electrical phase swap rather than a magnetic one. This is very similar in tone if not indistinguishable. However, I left it for a while and really enjoyed it. After some time, though, I missed my traditional "both on" tone. So I put the magnet back in with normal phasing and used a push/pull pot to swap the hot and the ground on the neck pickup. 2007/02/24 Update: Recently I've read a lot of posts in various forums where a lot of folks think that the "electrical" version of this mod can only be done with 4-conductor pickups. This is simply not true. I've presently got 3 Gibsons wired with push/pull or push/push switches that reverse a standard Gibson 2-conductor pickup's phase. Here's how you do it if you just want to do a phase reversal (no switch): 1.
Desolder the hot and the shield so the pup is free If you want to put a switch in like I did, check out this drawing. If you want to try this mod but you're a bit squeamish, buy a cheap used humbucker on eBay and do the mod on that one. This way you'll still have current one to fall back on if the deal goes south. The Infamous Jimmy Page wiring: I dedicated a whole page to this one here.
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This page was last updated 05/31/08
