Now it was structured around the JB/59 which the JB with a 250K pot is a common mod.
The 250k mod,
is the volume pot, not the
tone pot.
And if you're happy with a 250k tone pot, that's fine, it has nothing to do with a "The 250k on 10 is not reducing treble," as it is identical to a 500k pot turned to it's 250k measured point, which you could turn up if you need to.
Btw, here's my regular post that might help you if you want to experiment, hope it helps;
Different pot values and how they affect you!
Humbucker graph shown. (Supplied by Duncan)
Humbuckers traditionally come with 500k volume and tone pots, wth .022 caps. Single coils traditionally use 250k pots. Remember, pickups were voiced/made to run at these values, changing the value changes their intended tone (good or bad is an opinion), as well as their output.
The top curve indicates virtually no load, the second curve down indicates a 1meg pot, the third down is a 500k pot, the fourth is a 250k pot and the bottom curve represents a 100k pot. As you can see, higher pots give you more output and raise the resonant peaks output. The resonant peak doesn't shift in frequency, but it does shift in amplitude. The resonant peak frequency of most HBs is around 5k to 7k.
With tone controls (they react differently in the circuit), a 250k pot is the same as turning your 500k tone pot down to it's resistive mid point (5 on a linear taper pot). Even on 10, a tone pot bleeds high end to ground, but pickups were designed in this circuit in mind and some people think they sound cold and glassy without a tone pot in the curcuit. A lot of people in the 80's used guitars without a tone pot, but they also used some rack gear like a Yamaha SPX-90 that killed off anything over 8k, (the SPX-90II went to 12k) so it helped a bit to make up for the loss.
If you want to see what it's like to use different value pots, without pulling breakable knobs and changing out your pots, here's a
temporary way to see what it's like.

This is how you can hear what going from a 250k to 500k (or even 500k to 1 Meg) volume pot sounds like. Just disconnect the pickups output wire to the pot and put a 250k (or close, 240k or 270k), (or to try 1 Meg 500k or close), resistor in series.
It'll sound the same, but you CAN'T turn the volume all the way off, remember this is just a test function. If you like it, go buy the pot.
You can also try doing it to your tone pot as shown. In many guitars with 250k
tone pots, I've just left the resistor in permanently; you just can't turn it down as much.

This is how you can hear what going from a 500k volume and tone pot down to a 250k pot sounds like. Just put a 500k (or close e.g. 510k or 470k) resistor in parallel with the pots outer lugs. You can even leave it this way, the only difference will be the volume and tone pots taper (i.e. 10 will be 10, 0 will be 0, but it'll be half as loud at a
different place on the knob).
P.S. if your "or close" value is slightly higher then the pot, the value will be slightly higher on 10 then the actual double, (or halved value) in these circuits. If lower, it'll be slightly lower.
Edited by Armitage, 05 December 2010 - 05:14 AM.
I'm afraid that when I walk through those Asylum gates... It'll be just like coming home.