500k to 250k on one of the dials for tone. Adding a capacitor....Help

[shaneman]

I'm putting a JB humbucker in a rear routed strat body.  Warmoth is supplying me a 500k concentric pot.  It was suggested that i use a 250k pot to roll off the highs of the JB.  Warmoth is sending a capacitor to add to the concentric pot to make one of the 500k knobs a 250 knob.  Am I correct so far guys?  One 500 knob for vol....one 250 knob for tone ..all in one concentric knob.  Gotta convert one of these dials to a 250k. 

So, how do I do this?  Any and all input is appreciated.  Thanks, Shane

 

[Dan025]

I'm putting a JB humbucker in a rear routed strat body.  Warmoth is supplying me a 500k concentric pot.  It was suggested that i use a 250k pot to roll off the highs of the JB.  Warmoth is sending a capacitor to add to the concentric pot to make one of the 500k knobs a 250 knob.  Am I correct so far guys?  One 500 knob for vol....one 250 knob for tone ..all in one concentric knob.  Gotta convert one of these dials to a 250k.   

So, how do I do this?  Any and all input is appreciated.  Thanks, Shane

well there is a couple of things wrong with what you are saying. the capacitor can darken the sound but does not change the pot rating. i dont know what size cap you are referring to or how you intend to use it.

a 500k resistor can be used like you are saying but may change the taper a little if used on the tone control

some players prefer a 250K on a JB but it is not a rule, the JB is both hot and surprisingly bright so a lower pot value is not a bad idea, some even use a 250k for the volume pot.

using a 250k for the tone is exactly the same as rolling off the tone just a tad, maybe 7 or 8 on the knob if im thinking about it right. using a higher value can give just a bit more highs that you would not have access to with a 250k pot.

i wonder why a concentric pot exactly? is it to control the JB independantly? for a LP type thing or? an attempt to get 500k load for the JB and 250k load for the singles?
there are options that can use the conventional layout of strat controls that can work with HSH and SSH combinations.

 

[tfarny]

1. Why not just put it together with a 500k to see if you like it before modding it? Otherwise you'll never know what you like. 
2. The differences are minor, why not just roll off the treble with the normal 500k pot?
3. You can put a small cap to ground (say, .001 uf or .0047) anywhere in the hot signal path, which will take the edge off the highs and sort of approximate a 250k pot. But why do  you want that pickup then, if it's too bright to start with? How do you know it's too bright before you even try it?

 

[shaneman]

The strat body is routed for a single humbucker in the bridge location with a single hole drilled for a control pot.  You are correct about me not trying yet.  I may be just fine with it.  Many have suggested using a 250 pot to take the edge off a bit, so I figured I could use a concentric pot so that i could have a volume and a tone in one single hole location.  I was under the impression that you had to use a 250 pot for tone control.  Warmoth only sells the 500 concentric pot.  So, they suggested just adding a capacitor to change the value of one of the dials to 250.

Note: I also build paper rockets that fly to the moon. Can't you guys tell.  Sheesh :blob7:

Thank You ,Shane

 

[Superlizard]

It's odd, but the JB was designed to be mated with a 250k vol pot.

The pickup was originally for Jeff Beck's Tele.

However, in the hair-metal 80's, many a hair-popper had a hard rock maple guitar mated to a JB... mated to a 500k.

 

[shaneman]

Yes.  My strat is poplar and I've got a mahogany neck with an ebony fretboard.  The strat body was a steal and I couldn't resist.  I'm shooting for a polished relic antique early 80's super strat thing.  I've always been curious about the JB, so I picked up a gold JB trembucker, and a gold floyd.  I enjoyed the hell out of those early eighties guitarists.  It was fun and creative and you could still hear tone.  (I loved Dimartini, Gillis, Sykes, and Van Halen). 

Peace. :headbang: Shane

 

[Dan025]

The strat body is routed for a single humbucker in the bridge location with a single hole drilled for a control pot.  You are correct about me not trying yet.  I may be just fine with it.  Many have suggested using a 250 pot to take the edge off a bit, so I figured I could use a concentric pot so that i could have a volume and a tone in one single hole location.  I was under the impression that you had to use a 250 pot for tone control.  Warmoth only sells the 500 concentric pot.  So, they suggested just adding a capacitor to change the value of one of the dials to 250.

Note: I also build paper rockets that fly to the moon. Can't you guys tell.  Sheesh :blob7:

Thank You ,Shane

ok now i understand the concentric pot. but the cap has nothing to do with pot value. i mean a bigger cap will darken the sound and a smaller pot will darken the sound but they are not really the same.

a larger tone pot will have all the same sounds as a 250k but will have the ability to get brighter but will also be more sensitive.

a lower pot value will take the edge off buy limiting the range on the high end. a 250k tone turned to 10 is like a 500k tone turned down a little bit. the only real advantage is if the 500k gets so bright that it is not a usable sound in your playing then you can more easily dial in the sound with a 250k. both pots rolled all the way down will sound exactly the same.

a larger cap sized may darken the sound slightly with a 500k tone pot at 10. it might have a more noticeable effect with a 250k pot tuned to 10. with either pot rolled all the way down a larger cap will be much darker than a smaller one. the cap size is entirely player preference. i have used everything from .01uf to .1uf. it depends on the wood, pickups, and desired sound.

if you use a variety of sounds you may like a 500k with a .033uf or .047uf,

if you have a "signature" sound you may like a 250k and .022uf, or .033uf cap. if that sound is dark you may like a .033uf or .047uf. if it is bright you may want to go with a 500k pot and/or a .015uf cap.

with single coils you may like a bigger cap, with a very hot/fat pickup and/or a warm tone wood you may like the cap smaller and need a 500k pot.

with a bright tone wood you may need a 250k pot.

now about changing the value of the pot. a 500k resistor in parallel with the pot will change the value but may also change the taper, im not sure that will be a bad thing though, you should still be able to dial in the ideal sound.

the attached picture is a (crude) drawing of a pot as viewed from the bottom. a 500k resistor can be soldered from lug number 1 to lug number 2 to give an effective resistance of 250k.