No-load mod your guitar/bass tone or blender pot (2014)

Rob DiStefano

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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 (other pots such as Alpha and Bourns can also be no-load modded) ...

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.
DSC02491.jpg


Using the Xacto knife to get under the pot tab and lift it up just a little bit.
DSC02492.jpg


The needle nose prys open the case tabs.
DSC02493.jpg


Lift off the metal housing.
DSC02494.jpg


Lift off the fiber board carbon wiper tray with soldering lugs.
DSC02495.jpg


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 carbon.
DSC02496.jpg


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.
DSC02497.jpg


Reassemble the pot and use the needle nose pliers to push back each of the four case tabs.
DSC02498.jpg


Get those tabs pushed well pushed down.
DSC02499.jpg


All done, and the pot is marked as a no-load.
DSC02500.jpg
 

bender66

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Great pictures Rob & thanks for all your help.

*edit
DSC02494.jpg


Trying this with the Gibson pot we spoke of Rob. The threaded housing you show removed here doesn't come apart.
 
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Monotremata

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That's it seriously??? Please tell me I can do this with the stock pot in my classic 60s? Or do I need to buy that specific CTS pot? For all I know that might be what Fender uses heh.
 

Rob DiStefano

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Great pictures Rob & thanks for all your help.

*edit
DSC02494.jpg


Trying this with the Gibson pot we spoke of Rob. The threaded housing you show removed here doesn't come apart.

some pots are sealed and don't have those tabs that hold down the threaded post assembly that holds in place the carbon strip wiper board, and can't be made a no-load.
 

Rob DiStefano

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Excellent post, thanks. Would any modifications need to this technique need to be made when using a push/pull pot?

yes - a bourns push-pull pot can be made into a no-load. i do this all the time when wiring up a strat circuit, using the last tone pot as a no-load volume neck blender, and a bourns p/p is used as its underslung switch becomes the on/off for the dummy coil in the control cavity ...

CGCr7IM.jpg
 
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Rob DiStefano

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That's it seriously??? Please tell me I can do this with the stock pot in my classic 60s? Or do I need to buy that specific CTS pot? For all I know that might be what Fender uses heh.

if a pot has those side tabs that sandwich the tuner post bushing and carbon wiper plate, yes it can be taken apart and made into a no-load as in the pictorial above.
 

Davo17

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yes - a bourns push-pull pot can be made into a no-load. i do this all the time when wiring up a strat circuit, using the last tone pot as a no-load volume neck blender, and a bourns p/p is used as its underslung switch becomes the on/off for the dummy coil in the control cavity ...

CGCr7IM.jpg

Outstanding, im gonna give it a shot.
 

73Fender

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Thanks Rob, good tutorial. I saw another thread somewhere and the guy does this then adds a bit of nail polish over the scrapped area so you can kind of feel when it hits the no load region.
 

Rob DiStefano

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hmmm. i see no need to put anything over the scraped off carbon area as i see no viable benefit. with the pot knob fully clockwise, it sits on that dead spot and has maybe 1/16" of dead travel counter-clockwise before it sits on the carbon strip. fully clockwise and blocked means the signal is cut off, and then 1/16" (or perhaps 1/10th knob travel) and the wiper engages the carbon strip and begins shunting signal to cap and ground. fully clockwise is the tactile signal the pot and cap are both inactive.
 

bender66

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Reading more on this, someone made mention of doing the reverse, scraping off carbon when turned fully counter-clockwise/0, the signal is dead. Does this make sense?
 

Rob DiStefano

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Reading more on this, someone made mention of doing the reverse, scraping off carbon when turned fully counter-clockwise/0, the signal is dead. Does this make sense?

can be done, but then the sweep would go from off to immediate full mud tone to the least mud. it would appear to make better intuitive sense to be off and then increase the sweep of mud. but hey, to each their own. :cool:
 

73Fender

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Thanks Rob, worked great, just did my first one from my 72 Tele Custom before installing my new Fat Lion. Gonna see what a no load tone pot does to the humbucker, doing the single coil too.

I'll add that anyone who does this in the picture below from Rob, it looks like after scraping you'll see silver / metallic under the scrape, mine is more yellow looking (maybe scrapped a little deeper) ..I confirmed with an ohm meter that it is no load though.

I think it's a CTS pot (supposed to be it's an AVRI)..
labeled: 019064 250 k audio
DSC02497.jpg
 
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73Fender

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I'll also add that the little copper half moon looking trace that sits at the bottom of the shaft can move / rotate, I confirmed (assuming a wise move?) that mine was oriented as in Rob's picture before reassembling:
DSC02495.jpg
 

bender66

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Thanks Rob, worked great, just did my first one from my 72 Tele Custom before installing my new Fat Lion. Gonna see what a no load tone pot does to the humbucker, doing the single coil too.

I'll add that anyone who does this in the picture below from Rob, it looks like after scraping you'll see silver / metallic under the scrape, mine is more yellow looking (maybe scrapped a little deeper) ..I confirmed with an ohm meter that it is no load though.

I think it's a CTS pot (supposed to be it's an AVRI)..
labeled: 019064 250 k audio
DSC02497.jpg

What settings on your ohm meter & what lugs are you attaching/touching to get your reading? How does it read one direction vs the other? Maybe my meter is shot?

I'm still confused as to what's scraped in that pic. I see a scrape, AND I see a portion missing from the previous photo. I don't want to ruin any pots.

Thanks all.
 




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