"Selectable" pot values?

[Mini-Strat_Maine]

I haven't found a diagram for this yet, and thought I should ask if it's possible and/or practical. This may just be more proof that I have way too much time on my hands:
How about putting a parallel resistor on one (or maybe both) position(s) of a push/pull volume pot? Let's say you have an S/S/H Strat-type. It has one volume pot, and you've installed a good one, which you know the exact resistance of. (Not good English maybe, but bear with me.) We'll say it's an exact 500K, just to simplify any math, and your humbucker likes it just fine.
So how about changing its resistance to 300K, to make your single-coils happier without disappointing the humbucker? (This also kinda assumes that they're all individually switched for various combinations.) The 300K setting might be a workable compromise when all three pups are in use, or just the SCs.
It just occurred to me that you could also use it on an H/H (or even a 1H) guitar, just for some different tone when splitting humbuckers.

I'm guessing it could be done with a separate switch, but the push/pull pot would help avoid a Frankenstrat Switch Monster situation. (And I'm fishing for someone to diagram it for a push/pull, if there isn't already some "literature" on the subject.)

"Survey says . . ."

--
Doug C.

[JohnH]

My guess is that the sound difference between a 300k and a 500k pot would be very small, and you may decide that it is not worth the switch and hassle.

If you are convinced there is a worthwhile effect, theres no need for a switch. You could just hard-wire a fixed resistor across the singlecoil pup. One end of the resistor would connect at the point where its hot wire connects to the switches and the other to ground. This in combination with the 500k pot will convince the SC that it is looking at a lower resistance. When the SC is out of circuit, the the HB just sees the 500k pot. Both in parallel, it sees the 300k. Theres no switching to add.

What is the right value for this resitor? To convert the 500k to look like 300k, by the addition of a resistor in parallel, the theoretical value is 750k and the nearest standard value is 680K. You could also try 470K.

You could try this on one or both SCs. If you did it to both, the the 2SC combination would see about 200k, probably OK for this setting since its not that far from 250k which is often used., but all subject to personal choice.

To see if this is worth doing before a permanent installation, just put a resistor across your jack output (maybe by unscrewing the jack plug cover to get at the connections, and see if you can hear a difference in an A/B test. A spare 500k pot, connected across its outer lugs will substitute if, unlike me, you dont have a box stuffed full of random electronic parts in which to dig for a resistor

[UnklMickey]

maybe you could even incorporate with the existing tone switching side of the 5-way selector?

instead of a no-load pot, you'd have an always-load pot.

connecting the unused end of the tone pot to ground, and the cap to the wiper!

one pot for the 2 singles, the other (connected like a normal tone cut) as a master.

[UnklMickey]

johnh said:

... A spare 500k pot, connected across its outer lugs will substitute if, unlike me, you dont have a box stuffed full of random electronic parts in which to dig for a resistor

hey John, how many times have you dug in that box, and found resistors of every value know to man, EXCEPT for the one of the value you were looking for ?

[Mini-Strat_Maine]

johnh said:

My guess is that the sound difference between a 300k and a 500k pot would be very small, and you may decide that it is not worth the switch and hassle.

Okay. That was one of those things I was hoping to find out before I went diggin' around inside the guitar.

If you are convinced there is a worthwhile effect, theres no need for a switch. You could just hard-wire a fixed resistor across the singlecoil pup. One end of the resistor would connect at the point where its hot wire connects to the switches and the other to ground. This in combination with the 500k pot will convince the SC that it is looking at a lower resistance. When the SC is out of circuit, the the HB just sees the 500k pot. Both in parallel, it sees the 300k. Theres no switching to add.

Good idea, John.

Actually, the S/S/H arrangement I mentioned was "purely notional." The original idea was something I was mulling over for my single-humbucker Squier Bullet, once I add the on/on/on toggle for series/parallel/cut on its new pup. (I have a 500K push/pull pot that's presently unemployed.)

What is the right value for this resitor? To convert the 500k to look like 300k, by the addition of a resistor in parallel, the theoretical value is 750k and the nearest standard value is 680K. You could also try 470K.

Doh! Here I was, thinking 150K, forgetting that all the parts of a parallel resistance setup will divide, not just reduce the big one by the amount of the smaller one.
Oh, well, I did manange to find www.1728.com/resistrs.htm to help me do the math.

To see if this is worth doing before a permanent installation, just put a resistor across your jack output (maybe by unscrewing the jack plug cover to get at the connections, and see if you can hear a difference in an A/B test. A spare 500k pot, connected across its outer lugs will substitute if, unlike me, you dont have a box stuffed full of random electronic parts in which to dig for a resistor

Not yet I don't. ;D I do like the idea of being able to try any combination without really getting committed to something. (I think restringing a guitar after doing a mod is pretty close to getting a little kid all bundled up in a snowsuit. The guitar won't announce that it needs to go to the bathroom, but it just might not "say" anything.)

And UnklMickey, you know that's a subsection of Murphy's Law or something, about how the parts box is full of everything except what you need. (And you'll discover that you've run out of frammistats five minutes after the parts store closes.)

Thanks for the input, guys.