Pot values and differences in tone

[RaSTuS]

I know there is a correlation between the two, just not sure which way it goes.

 

I've just finished putting push/pull coil splits on a dual humbucker tele thinline copy, expecting a dual hum configuration would call for 500k pots, that is what I used. After removing the original pots I decided to measure them and they were 250k pots. Everything works as expected, but the guitar now has a really deep voice, I can't remember exactly how it used to sound before the mod because the guitar has been in pieces for the last few weeks getting nut and bridge upgrades at the same time, I also modded the 2 wire humbuckers to a 4 wire configuration (the new pups I ordered for it are on back order and I couldn't wait any longer).

 

Does anyone know what the difference in pot values would have on the final tone?

[Swoop]

500K pots are brighter due to the increased resistance to ground. This is why they're typically used with humbuckers. Humbuckers tend to be fairly dark, so 500K pots are used to make them brighter. 250K pots are typically used with single coils, (think typical Strat, Tele) as these pickups tend to be bright, so 250K pots mellow them a bit.

 

The StewMac website offers some excellent information about how it all works, which should make it clear.

http://www.stewmac.com/freeinfo/Electronics/Pots/w101-controlpots.html

[RaSTuS]

500K pots are brighter due to the increased resistance to ground. This is why they're typically used with humbuckers. Humbuckers tend to be fairly dark, so 500K pots are used to make them brighter. 250K pots are typically used with single coils, (think typical Strat, Tele) as these pickups tend to be bright, so 250K pots mellow them a bit.

 

The StewMac website offers some excellent information about how it all works, which should make it clear.

http://www.stewmac.c...ontrolpots.html

Brilliant articles Swoop, thanks for the link.

[BillyGibson]

Interesting article. What about mixing pot values between the tone and volume? I've had this question for a while and this thread helped me to remember it.

My Gibson std. had 300 volume and 500 tone with 57 HB's. Is that so the volume is darker but the tone is brighter? Because I believe Epi uses 500's for both.

So Epi's are brighter all the way around? How does someone decide what values to use for each p/u? What if they used straight 500's with the 57's?

 

Don't know if I'll understand the answer, just wondering.

[cjlandry]

I'm an electronics tech, but my ears aren't good enough for subtle nuances such as these. Otherwise I'd run the pickups through decade boxes and check all this for myself.

 

I'm just sticking with the 500K pots, since they can be turned down to anything between 500 and zero. The 250K and 300K pots can't increase their resistance any further.

 

Caps, on the other hand, aren't adjustable (at least not in these applications), so I think it's more prudent to check the tone with different capacitance values.

[RaSTuS]

I'm an electronics tech, but my ears aren't good enough for subtle nuances such as these. Otherwise I'd run the pickups through decade boxes and check all this for myself.

 

I'm just sticking with the 500K pots, since they can be turned down to anything between 500 and zero. The 250K and 300K pots can't increase their resistance any further.

 

Caps, on the other hand, aren't adjustable (at least not in these applications), so I think it's more prudent to check the tone with different capacitance values.

Sounds feasible cj, just checked the original cap and I'm pretty sure it's an 0.047uf, the new one I installed is an 0.022uf orange drop, from your experience, what theoretical difference should that make?

[cjlandry]

Sounds feasible cj, just checked the original cap and I'm pretty sure it's an 0.047uf, the new one I installed is an 0.022uf orange drop, from your experience, what theoretical difference should that make?

 

If it were a motor controller, I could help you. Since it's an audio application, it has to get past my tinnitus, so I can't help you there.

 

This guy explains it better than I could:

 

http://www.youtube.com/user/johnplanetz?blend=2&ob=1#p/u/4/rR4maqK_IhQ

[Whitmore Willy]

Great find CJ....

One of the best demos on the subject I have seen!

Thanks.

 

 

Willy

[animalfarm]

RaSTuS - Thx for starting the thread, produced GOOD results!

Never know WHERE the "good info" will appear.

 

"My momma said, Threads are like a box of Chocolates..."

RUN, Forrest - RUN!!!!!!!!

 

Swoop and CJ - both great links!

Now officially in EPI Lounge DIY sticky with due credit for

finding them.

 

Will come in handy for SOMEONE, SOMEWHERE, SOMEDAY...

[RaSTuS]

If it were a motor controller, I could help you. Since it's an audio application, it has to get past my tinnitus, so I can't help you there.

 

This guy explains it better than I could:

 

http://www.youtube.c...u/4/rR4maqK_IhQ

Fantastic link cj, great explanation in that video.

 

I know what you mean about the tinitus affecting your ability to discern audio frequencies, I have it 24/7 and at quite a loud volume, drives me crazy. I have to have some noise (tv,radio etc) running all the time simply to take my mind of the screaming whistle I'm alway experiencing, total PITA.

 

EDIT: Thanks for adding it to DIY animalfarm, you don't miss much do you.

[cjlandry]

Fantastic link cj, great explanation in that video.

 

I know what you mean about the tinitus affecting your ability to discern audio frequencies, I have it 24/7 and at quite a loud volume, drives me crazy. I have to have some noise (tv,radio etc) running all the time simply to take my mind of the screaming whistle I'm alway experiencing, total PITA.

 

EDIT: Thanks for adding it to DIY animalfarm, you don't miss much do you.

 

I really like John Planetz' videos. I have watched them all, some repeatedly. I'm not pleased with the electronic parts in Epiphone guitars, so I have to change them out when I get a new guitar. Even when I go with the same values, the quality of the parts makes a noticeable difference.

[bigneil]

I have always found there to be confusion between linear and audio taper pots and which ones are best suited to which application. Am i right in thinking that the linear ones roll off at a constant rate and the audio taper ones use some sort of exponential rate or something? which are best for what kind of pick-ups and which are best for volume and tone?

[RaSTuS]

I have always found there to be confusion between linear and audio taper pots and which ones are best suited to which application. Am i right in thinking that the linear ones roll off at a constant rate and the audio taper ones use some sort of exponential rate or something? which are best for what kind of pick-ups and which are best for volume and tone?

Your understanding of the differences between audio and linear taper pots is correct.

 

Gibson style guitars generally use linear taper for volume control, and audio taper [A] for tone control. Fender style guitars use the opposite configuration, or so I've been lead to believe.

 

As for which best suits certain pickups, I'm not sure.

[amx05462]

you can get more variations by trying different capacitors i like .033s in general.

[cjlandry]

I have always found there to be confusion between linear and audio taper pots and which ones are best suited to which application. Am i right in thinking that the linear ones roll off at a constant rate and the audio taper ones use some sort of exponential rate or something? which are best for what kind of pick-ups and which are best for volume and tone?

 

Logarithmic. The human ear and all the connections between the eardrum and brain, don't "hear" volume in a linear fashion, hence the audio taper pots.

 

Your understanding of the differences between audio and linear taper pots is correct.

 

Gibson style guitars generally use linear taper for volume control, and audio taper [A] for tone control. Fender style guitars use the opposite configuration, or so I've been lead to believe.

 

As for which best suits certain pickups, I'm not sure.

 

I opened up my Epiphone Les Paul Ultra today to check the pots. All four of them are audio taper. I'm replacing them with USA made audio taper pots, though.

 

 

you can get more variations by trying different capacitors i like .033s in general.

 

I prefer to go well below that, though I haven't made my decisions yet. It's nice having a capacitance decade box. I can connect two leads and try every possible value before making up my mind.