tone pot on '17 asat special

[john o]

Hi, I'm somewhat electronically challenged, so looking for a little advice.
I am going to replace tone pot on this guitar, doesn't work very well, and the guitar is pretty bright, would like a nicer, more linear treble roll-off.
I have looked at the schematic and have looked under the hood on a few asats to familiarize myself.
My questions are: should i replace the cap 1st, and if not happy with result, replace the pot? would that make a difference?
If i replace the pot should i get one from stew-mac or other equivalent parts supplier, or from G&L?
Is it advisable to stick with the same 250 pot?
a few pics for reference:

schematic in gallery


the guitar


this gtr pot/cap

[Tooslowhand]

When you say the guitar is too bright sounding, rolling off the tone control is what one would use to fix that. 250K Ohns is standard for these and most single coil guitars. If you put in a higher value potentiometer the roll off frequency will go higher and you will get less roll off, which doesn't sound like what you want. Guitar controls use audio taper pots which have a logarithmic roll off. Most of the roll off is in the last third of the knob travel. So for most of the travel you get only a small change, and the change is most dramatic in the last third of the knob travel.

If your issue is that you don't like that audio taper function, then you can replace the pot with a linear taper one of the same 250K Ohm value. If the guitar is U.S. made, then use a U.S. sized pot like CTS. You can purchase these from Stew Mac or other retailers. I suggest you get one that has a brass ferrule as they have smoother operation. If the guitar is a Tribute, then you need an Asian sized pot from someone like Alpha to fit the control plate opening.

If when you roll the tone control all the way down, you still think the guitar is too bright, then you could replace the capacitor with a larger value one. I would be surprised if you can't get the tone you desire using the standard values and manipulating the guitar and amp controls. You started this by saying you were electronically challenged, so before you pick up a soldering iron, consider whether you should take the guitar to a technician.

[john o]

Thank you, that's helpful.

its a usa asat. i think i'll go with the cts brass 250 from stewmac, and see what i get. i've been satisfied with the tone pots on my other asat's and a tele. this one just doesn't have a sweet spot.
should i use the cap that is on the gtr now, or obtain a new cap?
is there a standard uF range for the cap for a tone pot?

i can do basic soldering. i'm less sloppy now with some practice and a better quality (and hotter) iron. I can replace output jacks and fix cables. I don't mess with amps. they go to a tech. my knowledge of circuits is very limited, need to know basis only!

[Tooslowhand]

I suggest you keep the capacitor you have now rather than change multiple things at once. CTS makes both audio and linear taper potentiometers. I described the differences in prior post so determine what type of rolloff you want. If you just put a 250K Ohm audio taper pot back in it you will most likely end up with nothing changing unless something is wrong with the pot. Also examine all the solder joints to make sure nothing is cold or loose that might be effecting the functionality.

[john o]

thx again, much appreciated!

[john o]

I replaced the tone pot with a CTS 250k audio taper, looks same as what G&L uses. The cap I decided to use after a bit of reading was an "orange drop" 0.015 uF cap. I'm not sure what G&L uses (? 0.022, 0.046?), original is dark green and i can't read the #'s on it.

The result was as desired, a more gradual roll back of the treble, with the end point being not deep in the mud, but a more funky late '70's Brothers Johnson kind of sound, almost like what you get as you cock the wah wah pedal back, very usable. The original had no perceptible change in tone until i rolled it back more than 2/3 of the way, then rapidly transitioned to thick mud, not usable, no sweet spot.

I am happy with the result, got lucky 1st try, and did not mortally wound myself or the guitar with the soldering gun.