500k vs 250k volume pots- sound diff? Matching tone pots?

[mjsever]

I'm currently trying to figure out how to mellow the high end of the JB pickup I recently installed. I really like the string definition, responsiveness and tight low end (no more flubby low notes!), but not the shrill highs. Part of it is because it's a bright pickup, but it's also the guitar- the neck runs all the way through the body and the pickups are mounted directly onto the hardrock maple neck material so it's a very bright instrument.

Someone mentioned I could change the magnet, but that might be more trouble than it's worth and knowing me I'd end up ruining a perfectly fine pickup. So I'm thinking that a switch from my 500k volume pot to a 250k pot would be just the ticket. According to the SD site, this should mellow out the highs and bring the overall volume down a little bit (I wouldn't mind that either). Does this sound right? Also, will I then have to switch my tone pot to a 250k as well? And furthermore, is it recommended to switch the neck pup's volume to a 250k to balance it out?

Any help would be appreciated.

 

[Scott_F]

This 500 to 250 JB Trick came from the keyboard of Seymour himself several months ago. So, it's an inexpensive experiment.

I'd probably leave my neck pup at 500k if I was happy with it. Again, it'd be a cheap try either way.

I'm not sure about the tone controls. My gut instinct would be to leave them alone.

 

[Fresh_Start]

Instead of replacing the volume pot, you might want to try a "synthetic" 300k pot by putting a 750k resistor across the outside terminals of your existing 500k volume pot.

Scroll down a ways in John Spina's tutorial on pots: http://www.projectguitar.com/tut/potm.htm

Note: this will make the taper of the pot a bit more gradual than a normal audio taper pot - but it still won't be close to a linear taper.

Changing the volume pot should have a greater effect than changing the value of the tone pot, so you might want to try changing the tone pot first. The 750k resistor(s) are dirt cheap and are really easy to add/remove, so you don't have much to lose

Chip

 

[SfordRog]

Might also try height adjustment on the treble side or a diff value cap. I've used mixed value caps in the past (one for neck, different one for bridge....might take some getting used to though). Good luck.

 

[mjsever]

Wow- this is a much easier solution than I had envisioned. Since this is my first time doing this sort of thing, I would feel much more comfortable soldering in a resistor than removing/desoldering and installing/resoldering a new volume pot, especially since it's a push-pull coil tap! Then if I don't like it, it is sooooo much easier to undo. I might even try playing around with the tone caps to tweak it just so...

You guys rock. Thanks a million!

 

[Kent S.]

The only thing with the resistor trick is that it does alter the taper of the pot, but a lot of people find this favourable ...
Other things you might want to try that are pretty non-work load involved are :
Putting a small value cap say (100pF~470pF ) from the hot of the JB to ground, that lets you keep your lower mids and volume closer to being the same, while shifting the peak down without stepping on it to much ...
Or if you want to mess with the tone pot, a lower valued control pot, and a smaller valued cap ...
Of course adjusting the pup itself (as pointed out) can do wonders a far as string balance issues.

 

[STRATDELUXER97]

The only thing with the resistor trick is that it does alter the taper of the pot, but a lot of people find this favourable ...
Other things you might want to try that are pretty non-work load involved are :
Putting a small value cap say (100pF~470pF ) from the hot of the JB to ground, that lets you keep your lower mids and volume closer to being the same, while shifting the peak down without stepping on it to much ...
Or if you want to mess with the tone pot, a lower valued control pot, and a smaller valued cap ...
Of course adjusting the pup itself (as pointed out) can do wonders a far as string balance issues.

Fresh Start and Kent are both right...The resistor trick gets you the 300k value but it also will change the taper...The JB was designed around the 250k pot,so if it were me,I'd just switch out the volume pot...In everyone of my fullsized bridge humbucker strats and regardless of the humbucker I use,I always prefer the 250k value...The resistor tweak is quick and easy and you could try that first?You may like it fine that way..

John

 

[Ken]

.The JB was designed around the 250k pot,so if it were me,I'd just switch out the volume pot...

My thoughts exactly. Didn't Seymour use the original pots from Beck's guitar when he wound the new pups for him? I could be totally off. Wish somebody would post a link to that "History of the Tele-Gib" thingy.

 

[psychodave]

Instead of replacing the volume pot, you might want to try a "synthetic" 300k pot by putting a 750k resistor across the outside terminals of your existing 500k volume pot.

Scroll down a ways in John Spina's tutorial on pots: http://www.projectguitar.com/tut/potm.htm

Note: this will make the taper of the pot a bit more gradual than a normal audio taper pot - but it still won't be close to a linear taper.

Changing the volume pot should have a greater effect than changing the value of the tone pot, so you might want to try changing the tone pot first. The 750k resistor(s) are dirt cheap and are really easy to add/remove, so you don't have much to lose

Chip

I use old Gibson 300k pots for almost everything. I never liked the muddyness of a 250k and the brightness of a 500k. With that being said, I do like 500k pots in a LP's.

 

[Kent S.]

Fresh Start and Kent are both right...The resistor trick gets you the 300k value but it also will change the taper...

John

Oh course if I had not read it so quickly, I might have noticed that Fresh Start had already mentioned that ... :smack:

 

[StrangeDay]

I'm absorbing way to much info for one day. Soon, I will understand your rheteric!!

 

[mjsever]

even easier way of approximating pot change?

even easier way of approximating pot change?

For those of you who are still interested, I just found an even easier way to emulate the sound of replacing a 500k with a 250k pot.

"Turn the guitar volume up all the way. Get a 470k or 510k resistor from Radio Shack or wherever --low wattage is fine. Unscrew the sleeve from the 1/4" plug going into your guitar. As you are playing, have someone hold the resistor across the two connections and see if you can tell the difference. Paralleling your 500k volume pot with the 470k resistor simulates changing to a 250k pot."

http://uts.cc.utexas.edu/~mic/info/guitar/Correct-Pot-Value

I'd like to pose the following questions to all the experts who've already been so helpful:

Do you have any opinion or rationale as to whether this might be any different from bridging the volume pot? Also, does anyone have an opinion as to whether bridging the portion of the cord going into the amp would do the same thing? (that would certainly make it easier for the person playing the guitar and the person holding the resistor).

Thanks again everyone!

 

[Big String]

Does this 500k to 250k work for the bass pup's too.?

 

[mjsever]

Ahhh good point; I do have separate volumes for neck and bridge. Apparently this would approximate the sound if BOTH volume controls were changed to 250k, as opposed to just changing the bridge pot. While I'll be able to test each pickup separately, I won't know how both pickups would sound together if I kept the neck at 500 and changed the bridge to 250.

Still, it's an even quicker way to get a "trial run" of a new tone than soldering in a resistor and de-soldering if I don't like it. If I do like the change I will take everyone's advice and change the volume pot altogether.