Modifying volume and tone pots

[tonequester]

tonequester here.

Does anybody have experience with modifying volume and/or tone pots, to which the cover is removed and an x-acto knife is used to scrape off some of the resistance path, to allow for full output in the "wide open' position. I am getting things together to replace pick-ups and completely re-wire my Kramer Strat clone, and am thinking of doing this. I would like to know if it is a real b----, any tips, etc. i am using Stew-Mac CTS pots. 1 meg for the volume and 250k for both tone controls. Is it worth
the effort, in the change in sound one might expect ? Any comment is as always, quite welcome in advance. tonequester.

[soundguruman]

No, I wouldn't modify it with an x-acto knife. There already IS full output in the full on position.
whoever told you to do this is mental.

[Steve Conner]

It won't work with a volume pot. You would get pretty much full output in any position, or if you cut the other end of the track, no output at all.

With a tone pot you can scrape away the clockwise end of the track. Or you can buy it pre-done, it is called a "No Load Tone Pot". Fender No Load Guitar Tone Pot-Split Shaft I recommend buying the factory-made one in the interest of long-term reliability. A hand-scraped track might disintegrate on you after the wiper has been over it a few hundred times.

I believe my reissue Strat has one of these pots in the bridge tone position, and it certainly has lots of crunch and bite with the tone turned up to 10.

[rjb]

With a tone pot you can scrape away the clockwise end of the track.

An alternate way of doing the same mod is to carefully paint the track with nail polish, insulating it from the wiper.
I can't speak for the long-term reliability of either method.

[tonequester]

tonequester here.


Greetings Steve. Thanks for the lead on the Fender- no load pots. This mod is all over the web, and has been recommended in books for years. In Gerald Weber's 1997
book : Tube Amp Talk for the Guitarist and Tech, he has re-printed much of the Trainwreck Pages(Trainwreck Amps, by Ken Fischer,founded 1981) and the mod appears there. Gerald Weber
founder of Kendrick Amps, after outlining the mod states : "And now a word to the guitar companies...I've been using and teaching this trick for over 30 years. Don't go running off to the patent office, it won't stick ! I didn't think that it would be of use with a volume pot, but figured I'd cover all bases. If I've learned one thing on this forum, it's don't take anything for granted, when you are just getting started in electronics at the basic level. It gets to be a chore in itself for one like me to sort all of the opinions and advice out, once you've got them.
As to the effect itself, it sounds like from your personal experience, the mod would be well worth the extra $2.00 a pot, especially when factory made. Thanks once again my friend !
Thanks as well to rjb and soundguruman for your relpies. tonequester.

[Sweetfinger]

It won't work with a volume pot.

Where there's a will, there's a way.

[tonequester]

tonequester here.


Greetings Sweetfinger, and pleased to "make your aquaintance". Hell, I don't have a clue whether it will work or not, but I like your attitude. I might just buy a cheap pot and try it out. Enzo keeps reminding me that "hands on" experience can't be replaced with any amount of book work. I'm thinkin' you really need both in order to excell, but I sure do like
tearin' things apart anyway. I've run onto the strangest things during my years of "disassemblement". Keep that finger in the sweet stuff ! tonequester.

[Sweetfinger]

Oh, it'll work. You just have to think "outside the standard wiring diagram". As far as physically opening and re-assembling pots, I primarily work with the CTS pots. You need to find just the right set of cutoff pliers to uncrimp the tabs cleanly and just the right size of longnose pliers to bend the tabs back into place. I have a set of wire strippers that works pretty well for that as well- mine have a semi-circular cutout used for crimping house wiring. It is just right for cradling the opposite edge of the pot housing while bending the tab back into place. I've been doing it since about ten minutes after reading the Ken Fischer article in the 90s. The Fender no-load pot is nice... unless you don't want the detent or need the cut in the track to be somewhere else.

[tonequester]

tonequester here.


Thanks for the reply on the pot mod Sweetfinger. It sounds like you've got a pretty good methodology. Damned, if the right tool for the right job isn't true. I have a couple of 250k tonepots that are cheap, probably Radio Shack. I thought that I'd try my luck on one of those. No big loss if I screw one of those up. The CTS pots(esp. with shipping) are just too expensive to take a chance on, at least until you have it down pat. What gets me is that like you, I read about the mod years ago, and yet for some unknown reason never gave it a second thought until I started to upgrade the Kramer. The Good Lord knows that I've monkeyed with everything else possible on electrics. Hey ! You have a great day! tonequester.

[David Schwab]

Where there's a will, there's a way.

No, when you get to 10 you will have no sound because the circuit is now open.

A no load pot works on a tone control because on 10 you want the circuit open.

Just get a push/pull pot and wire up the switch to take the volume control out of the circuit and wire the pickup to the jack.

Or get louder pickups.

[soundguruman]

There is no "amazing improvement" for a no load pot.
It's a slight treble boost if the tone pot is open. A slight amount...
you can scrape it, but later...you will replace it.

[tonequester]

No, when you get to 10 you will have no sound because the circuit is now open.

A no load pot works on a tone control because on 10 you want the circuit open.

Just get a push/pull pot and wire up the switch to take the volume control out of the circuit and wire the pickup to the jack.

Or get louder pickups.

tonequester here.


Greetings David ! I like your idea about the switch. A much simpler way to drop out the pot. I do have new pick-ups in the works, with new pots and 5-way. I pretty much
chose the pick-ups(Bill Lawrence) from previous experience with them. I'm not sure how they rate for output, but I sure liked the over-all tone they produced at that time. I'm going to try his Q-filter as well, but I'm going to make it switchable. I heard a You Tube demo of the LRC filter which was impressive, and it only runs $24.00. Lawrence's pivk-ups are very reasonable as well. The humbucker(stacked) that I'm placing in the bridge position is $54.00. The pickups are constructed mod-unfriendly, but nearly indestructable. Thanks for the advice on switchable pots, it never even occured to me for a volume control. Have a great day ! tonequester.


Qoute : 'Where come I, and whither go I ? That's the great unfathomable question, the same for everyone of us. Science has no answer for it." Max Planck.

[Chuck H]

FWIW, and JMHO, but... There's no real advantage to bypassing the volume control load. If you wanted to be absolutely sure your getting maximum output and response from a hot pickup just use a 1M A10 taper volume pot. There will always be a load of at most 1M on any amp input (EDIT: Some early grid leak input designs being an exception). Parallel that with a 1M on the guitar volume control and then the impedance of the pickup @ frequency. Now map the actual physical difference in loads and how that impedance affects the frequency response. The difference is truely useless for average guitar use. Unless your plugging into a purely reproduction amplifier and using a speaker cab with a tweeter in it you probably won't even hear a difference between a 1M pot full up and direct connection to the jack. So at that point it's just an extra switch to fail at some point. Why complicate it? The no load thng for a tone pot makes more sense because high value tone pots have a crappy taper. Even log pots. So lower values are often used. Ibenez used a tone cap lift switch on early JS guitars. This would be the same function as the no load pot. Joe said it was an important part of his sound.

JM2C

[tonequester]

tonequester here.

Hey Chuck H. Glad to here from you. I here where you are coming from. No sense to fool around with a volume pot that's already giving me all it can. Steve Conner replied
about this issue in agreement as did others. I'm already using a 1 Meg volume pot. My tone pots are 250kOhm and cheap pots at that. I've already received 2x 250kOhm CXTS pots from
Stew-Mac. I wish I hadn"t ordered them, as Steve clued me into Fender Drop out pots, which have the zereo resistance mode with a click in detant. I'm not sure which way I'll go yet.
I pretty much have to make several orders, spread out over a few weeks in order to get all of the pick-ups,pots,switches,wire,etc., to do the whole circuit re-do. I've found an amp kit (tube)
as well that i'm trying to swing this month as it is on sale-10% off this month at Antique Radio Electronics. A MOD 102 kit, Class A,S.E.,cathode biased hand wire job. At 10% off of $215.00
it seems a good deal, as well as a good starter kit for me. It uses one 12ax7 and one EL-84 to produce 5 big Watts. loudthud checked it out, as a matter of fact he found the sale at A.R.E.
and he thought it looked pretty good for the price. If you should get the time to take a look at it, or if you already know something about it I'd appreciate your opinion as well. The chassis ipre-punched steel/painted gun blue. It has Hammond transformers, and it sounds like the directions and drawings are good, with on-line support as well. Thanks again for the reply.
Tone pots yea,......Volume pots ney. Have yourself a great one ! tonequester.

[Chuck H]

Sorry I don't know the kit. I like the idea of a gun blue finish though. I've been blueing my non stainless pocket knives since I was twelve. That and a wipe of oil now and again and they'll out perform almost any stainless pocket knife in normal use. Not too sure about wiping a chassis down with honing oil though

Just make the no load pot for your tone control. Regardless of what anyone has said it will not reduce the longevity or reliability of the pot. On most pots you just bend the tabs that hold the casing on the pot and lift it off, exposing the wiper and the resistance track. There is likely a defined margin where the track meets the resting tab that the wiper sits on when the pot is fully rotated. Be sure to identify the correct end of the track. Use an exacto blade turned backwards (you don't want to just cut the track, the gap needs to be a little wider than a cut) and scratch the track away where it meets the tab. Blow clean and test. Repeat as needed. Then put the back on and mark it with a sharpie (in case it ever ends up back in component circulation). You may want to include a 10M resistor from the center lug to the no load lug. Some effects do place a small DC charge on the line and this could cause a small pop sound if the cap doesn't keep a 0VDC reference.