volume pot taper tweak?

[daz]

Thats a typo. I meant 375k. I'll change it. By the way, they are usualy 20% tolerance soe they CAN be higher. I have a 250k labeled pot that measured 300k recently.

[Enzo]

I think he may have meant the measurement to the wiper from one end cannot be higher than end to end. A "450k" pot can measure 475k, but you can't have a pot measure 450k end to end and then measure 475k wiper to end.

[daz]

Doh ! I see. In any case, i wonder if a linear pot would get me what i want. After all, at 50% rotation it would be a lot closer to what i'm after. 250k vs what is now about 75k. I'd have to rotate the current pot to where it gets as clean as i want it to be on 5 then measure it and see how close linear would get me.

[pdf64]

Doh ! I see. In any case, i wonder if a linear pot would get me what i want. After all, at 50% rotation it would be a lot closer to what i'm after. 250k vs what is now about 75k. I'd have to rotate the current pot to where it gets as clean as i want it to be on 5 then measure it and see how close linear would get me.

A linear pot will have far more output at 50% rotation than your current pot, so at a setting 2-3 you would have more overdrive than now; that's surely in opposition to your goal?
If your current pot is 75K at 50%, then its taper seems to be 15% audio; several manufacturers use that as their standard audio taper, eg Alpha USA.
My guess is that a well implemented 10% taper pot would suit you better; Bourns have a good rep,10% seems to be their standard audio taper, and they have a range of guitar specific pots.

[daz]

A linear pot will have far more output at 50% rotation than your current pot, so at a setting 2-3 you would have more overdrive than now; that's surely in opposition to your goal?
If your current pot is 75K at 50%, then its taper seems to be 15% audio; several manufacturers use that as their standard audio taper, eg Alpha USA.
My guess is that a well implemented 10% taper pot would suit you better; Bourns have a good rep,10% seems to be their standard audio taper, and they have a range of guitar specific pots.

Ok, well i didn't take note of the side of the pot that was 75k but i assumed when i measured it that the 75k was between the wiper and input which would be worse for what i am looking for. I assumed that because it made sense as to why there was little effect at 50% rotation. I suppose i should measure it again to be sure but looking at pots just now it seems very few spec the taper %.

[mozz]

Alpha, Bournes, Cts, should all have datasheets on their websites. Like i said, the pot could be worn out, the fingers could be riding on hardly any material therefore you would read high. The overall resistance would not change as there would be places the fingers do not touch.

[Helmholtz]

In my experience worn out pots typically show increased overall resistance and/or uncurable scratchiness. Another indication could be reduced (!) output at 50% travel.

[daz]

The pots/guitar are 2 months old.

[mozz]

What's the make/model of the guitar? Most everything is linear vol today and i think Gibson is using 300k.
Just measured 10 pots, mostly new. All full sized, different makes cts bournes alpha, korean, unnamed, stackpole.
You seem to have more taper than any of these. Full reading, 50% reading.
493k-451k
496k-440k
560k-483k
490k-419k
518k-440k
522k-451k
475k-425k
458k-381k
511k-465k
457k-362k

[Dave H]

mozz, you must be measuring from wiper to cw end which would make most of those 10% audio taper.

[mozz]

Yes, from one end to the wiper. To the original question, swap out to another pot. Either that or you are using a very high gain pedal or amp input. OP said 450k =375k/75k @50 % is more of a taper than any i have listed. Maybe the tone cap is shorted or leaky, there are only so many things to go wrong with 2 pots and a cap, change them out.

[Helmholtz]

The 15% dead zone at the start of CTS audio tapers is somewhat off putting.

Have you tried to remove some of the conductive silver paint in the dead zone with acetone on a Q-Tip?

[pdf64]

Have you tried to remove some of the conductive silver paint in the dead zone with acetone on a Q-Tip?

No, has that worked for you?
I just tried some judicious scraping at the outside edge of the metalised 'dead zone', but the metalisation seems to go all the way through to the substrate, rather than being on top of the resistive element.

[Helmholtz]

.. has that worked for you?

Haven't tried yet. Was just curious if acetone or extra fine steelwool would work. Up to now the dead zone hasn't been a problem for me.
My main problem is to find strat pots that actually measure 250k or above. I feel that -20% pots dull the tone. So I sometimes transplant wafers. I've heard of people who increase resistance by using fine emery paper or steel wool on the track.