250k vs. 500k - a new discussion (really)!

spauldingrules

Senior member
Messages
720
Ok - I am doing a HH guitar, and I have a 250k and 500k pot.  Will there be a difference with 500k on volume and 250k on tone vs. 250k on volume and 500k on tone?  I'm using a .223 cap.  I want it a little darker (hence one 250k pot) that two 500k pots.

Thanks in advance!

TS
 

bob7point7

Senior member
Messages
272
Well, I've never played with mixing pot resistance, but I'll take a stab at anwering your question. The impedance of the capacitor is small compared to the tone potentiometer, (whether it's 250K or 500K) and they are wired in series, so the overall impedance of the tone circuit when the tone is at 10 will basically be the pot value. The impedance of the volume circuit will always be equal to the value of the volume pot. Therefore, the pickups should see about the same impedance when the tone pot is at 10 no matter which pot is used in which position. The big difference should come from the actual signal that ends up going through the tone cap. Using the 250K pot for tone should allow more signal to go through the capacitor at any knob position above 0, meaning more highs will be rolled off. When the tone knob is turned to 0, the tone pot would be shorted out, so it wouldn't matter which pot was being used for tone. Overall, using the 250K pot for tone should give a darker sound with finer control over the tone, while using the 500K pot for tone should give a wider range on the tone control and a brighter sound when the tone is at 10. Is the cap really 0.223 uF or is it 0.022 uF? 0.223 seems very high. If the cap is 0.022uF you might want to consider picking up a 0.047uF cap to roll off more high frequencies. I hope this all makes sense.

Good luck,
-Bob
 

DiMitriR33

Senior member
Messages
604
the impedence of the cap is frequency dependant. it will only be low at a very high pitch. at a low pitch it acts as an open circuit.
it will only come in to play when it is near or less than the setting on the tone pot. this is at a very high (inaudible) pitch at even 250k.
the tone pot value may influence the presence slightly but you probably won't notice it. changing the pot value will however change the sensitivity in the control.

the volume pot is the main factor when the tone is at 10.
anything else and the cap will have an effect.

i would suggest a larger cap. unless you have very hot and bright pups. hot pu's are less afected but the pot but tend to be less bright anyway. but the duncan jb is often used with a 250k to mellow it out a bit.

btw a cap marked something like 223j100v means 22 x 10(exp -3) micro farrad. or was that 22x10(exp3)pico farrad. now i can't rember but the 3
simply locates the decimal point relative to a standard unit. i'd guess you have .022 micro farrad cap.
 

confederatewk

Senior member
Messages
116
always have a higher value for volume and a lower value for tone, then ur tone stays when u turn down the volume a bit

otherwise youll get very little volume responce the other way around

and for a hh setup, id recoment just getting the 1 meg pot for volume and a 500k for tone with a .022 cap

thats a basic and standard for tone i beleive, ytou will get more responce, and you will get beter harmonics with a higher pot value no matter what pickup u use
 

-CB-

Senior member
Messages
5,427
I just changed my tone pots on the thinline with the goncalo neck and ash body.  From 250k to 500k - marked difference.  And it seems like you can dial in more subtle variations, but that could be the taper and or just how things worked out.  I'm trying to brighten things up a wee bit, and that seemed to help a good deal.
 

TonyFlyingSquirrel

Senior member
Messages
4,230
Here's a question:
Say that you don't use a tone pot, like myself, but you want the most transparent tone to come through, very little if any coloration to the tone.

Do you go with a 1mg vol pot? If so, do I use a cap with it, if so, what value?  I want no loss of highs.
 

DiMitriR33

Senior member
Messages
604
TonyFlyingSquirrel said:
Here's a question:
Say that you don't use a tone pot, like myself, but you want the most transparent tone to come through, very little if any coloration to the tone.

Do you go with a 1mg vol pot? If so, do I use a cap with it, if so, what value?  I want no loss of highs.

no tone pot = no cap. unless you do the treble bleed mod.
a 1 meg will generally brighten things up, certainly won't make it darker. but this is technically a form of coloration. there is a little hump in the upper end of a pickups responce. a higher value pot raises this hump. a low enough value pot can about eliminate it. but thats not usually desireable.
some very hot pups are less afected by pot values. i saw a graph of frequency responce for a duncan invador with diferent pots. it had a slight change in output but didn't affect the balance much.
don't get too caught up on anything confederatewk might have said about anything. he seemed to be an advocate of huge value pots for reasons he clearly didn't understand.

a 1-meg pot and no tone is exactly how my telecaster is wired, i like it, it seems to work well with my pickups. if you use a high enough value tone pot it won't have an audible effect at 10.and you can always wire it up to a switch or a no load pot if you can find one.
1-meg might not have an affect over 500k on some pups. also highs may get strong enough to overpower the lows making the guitar sound thin.
it all depends on your pickups and your ears.

beyond that there may be things to do to your pickup to get some more brightness. the metal covers on SOME pickups, not all, can change the sound for reasons i don't have an explaination for but tend to make it less bright. also i've read that if you shorten the adjustable pole peices on a pickup it can become more bright. acording to seymour duncan it helps focus the magnetic up twards the string, long pole peices draw it out the botom of the pickup and reduce power and treble.
 

TonyFlyingSquirrel

Senior member
Messages
4,230
I use an Evolution Bridge, and an Air Norton S.

My main concern is that I seem to lose some highs as I roll the volume pot back to about 5 from 10.  It comes across a little too spongy for my taste.
 

dbw

Senior member
Messages
4,531
TonyFlyingSquirrel said:
I use an Evolution Bridge, and an Air Norton S.

My main concern is that I seem to lose some highs as I roll the volume pot back to about 5 from 10.  It comes across a little too spongy for my taste.
http://alexplorer.net/guitar/mods/hipass.html
 

DiMitriR33

Senior member
Messages
604
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=treble_bleed

like this one better.
 

dbw

Senior member
Messages
4,531
DiMitriR33 said:
http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=treble_bleed

like this one better.

Cool, that'll give you the treble boost without changing the curve of the volume knob as much.  Thanks Dimitri!
 

TonyFlyingSquirrel

Senior member
Messages
4,230
That's the one I was thinking of.
My old PRS CE-3 had pretty much the same circuit in it.
Very smooth transition, very even balance in tone when rolling back the volume.
 

Rick

Senior member
Messages
4,154
Also, your amp has an affect on the sound.  Some amps are "tuned" to be darker or lighter depending ...
 
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