Tone Control

[Gibsonman63]

I picked up an early sixties Melody Maker. There is not much there, so I am going to put some decent tuners and new pickguard, electronics, etc on the guitar. I normally do not use my tone controls and run them out full treble. For this guitar I am thinking of putting one mini-humbucker in the bridge position and one volume knob with no tone control.

Even though I don't use the tone control on my other guitars, does it still color the sound?

[pdf64]

No tone control will reduce the load on the pickup, allowing the resonant peak to be higher, which will likely increase the perceived treble a little. If you want to compensate for that, use a 250k vol pot, rather than 500k.

[Mark Hammer]

The series resistance of the tone pot at max treble does not act exactly like an open circuit. It merely provides enough resistance that the signal bleed, at the frequency rolloff dictated by the cap value, does not stick out like a sore thumb. Total elimination of that path, by either use of a "no-load" tone pot that goes open circuit at the extreme of rotaton, or by having no tone pot at all, will often result in a marginally detectable increase in treble. Ultimately, the detectability of it will depend on:
a) how much treble there is in the pickup to start with, and how much the rest of your signal path allows that treble to be audible;
b) the value of the volume and tone pots to begin with;
c) the setting of the volume pot;
d) where the tone pot is situated, in relation to the volume pot.

D is noted last, because most guitars, especially single PU models like you describe, will have the tone pot connected to the input lug of the volume pot. The odd case will be wired differently, though.

Since this is a vintage piece, the best thing to do, from a resale perspective, is to simply unsolder one end of the connection from the tone pot to volume pot, and tape up the loose end. That way, the tone control is disabled, but you won't have lost any of the original parts, and any subsequent owner (heck, maybe even you) will have the convenience of a piece of wire cut exactly to length.

[Gibsonman63]

Thanks for the info guys.

It is a vintage piece, but at this stage it is more of a project than a guitar. The guitar has been stripped (not by me), but fortunately, the headstock was not stripped. Right now, it has no hardware and no electronics, just the stripped body and the tuning keys, which I plan to replace.

Based on the condition it is in, I plan to turn it into a cool player's guitar rather than a full up restoration, but I am not going to go crazy with it.

It sounds like I need to buy an 250k and a 500k ohm pot and let my ears decide.

[Rob DiStefano]

if the 'tone pot' (rather, 'tone sucker' since all passive eq just shunts treble to ground) is a cts or other decent make, open it up and remove about 1/8" of the carbon from the right side of the wiper strip, just in front of the input wiper lug, reassemble the pot. this makes it a no-load so that when fully dimed clockwise the pot and cap are totally out of the circuit, cracking the pot less than 1/4 turn ccw will kick it back into the circuit. if, for 'vintage reasons', you don't wanna mod the pot, replace it with a cts and mod it as just described, or spend twice as much for a ready-made no-load pot (fender).

my previous pictorial on creating a no-load pot ...

Why a no-load pot? More than a few reasons but here are my two faves -

It makes the perfect neck blender pot for a Strat because unlike using pot resistance to null out the neck pickup, a no-load pot is a switch that totally turns off the pup so no signal bleeds to the output.

There is no question that at higher volumes you'll hear the difference in yer pups' tones with the tone pot removed from the ciruit.

OK, here's how I mod a CTS pot to no-load ...

A CTS 250K audio taper split shaft pot, a pair of needle nose pliers for bending the pot tabs open and close, an Xacto knife to start the bending of the pot tabs, a single edge razor blade to remove the part of the carbon resistance strip that'll make the pot no-load.


Using the Xacto knife to get under the pot tab and lift it up just a little bit.


The needle nose prys open the case tabs.


Lift off the metal housing.


Lift off the fiber board carbon wiper tray with soldering lugs.


Flip over the tray - there are three solder lugs on the left, where the carbon strip meets the upper lug is where we wanna remove (scrape) off about 1/8" of the plating and carbon.


The single edge razor blade has scraped off about 1/8" of the wiper's copper plating and black carbon film, right near that upper soldering lug.

[Rob DiStefano]

Reassemble the pot and use the needle nose pliers to push back each of the four case tabs.


Get those tabs pushed well pushed down.


All done, and the pot is marked as a no-load.

[Gibsonman63]

This was a project guitar when I got it, so I just got the guitar, not any of the electronics or hardware. I ended up using a 500K pot and installed a Seymour Duncan mini-humbucker. The guitar is a real screamer, or at least it was before I disassembled for finishing.

Neat little trick. I have seen this before to disable the vibrato (and add 3db) on the BF Fender amps, but I have never tried it.

[WholeToneMusic]

Mojo also sells the no load pots if you don't want to disassemble your own.

[ReginaldBisquet]

Neat trick with the no-load pot! I have several spare pots laying around... will experiment.

Why not add a treble bleed circuit to the volume pot?