Two tones - Share cap or not?

[xld]

Howdy,
My build is a 2 humbucker, 1 Volume, 2 Tone, 3 way switch. I have wired a capacitor on EACH tone control.
Works exactly as expected except it seems that when in middle position, both humbuckers on, there is quite a tone drop…minimum brights and a little muddy. (It’s not “out of phase”.)
Questions: Am I doubling up capacitor value while in middle position? Would one “shared” capacitor produce better results?
I have seen diagrams showing both options but no explanation as to the reason for the two different diagrams.
Thanks!

 

[triple jim]

Yes, with two capacitors the effective capacitance is the sum of the two when both pickups are on. Two capacitors lets you have different values for the two pickups, but having only one prevents adding the two in the both-pickups position.

 

[mayfly]

To add to what Jim said, both of those capacitances in parallel in the circuit will drop the frequency of the 3db down point in half. So yea, that would make it muddy.

 

[xld]

Thanks much guys, I appreciate the confirmation/clarification!
Now to decide whether the center position is an option I’d like to have available or not. To my ear, it’s useless as it is now.

 

[triple jim]

To my ear, it’s useless as it is now.

Even with both tone pots all the way clockwise?

 

[Strat Avenger]

Never understood why some guitars are wired with individual tone caps while others are wired with a shared cap.
The Yngwie Malmsteen signature Strat has individual tone caps (the tone controls are disconnected on his personal guitars) while the Eric Johnson model and the American Standard Strat have a shared cap.

 

[xld]

Even with both tone pots all the way clockwise?

I understand...
With tone pots cranked the effect of the capacitors is eliminated.
"Useless" because I would never play with the tone pots wide open.
Thanks for making sure I was on the right track!

 

[xld]

Never understood why some guitars are wired with individual tone caps while others are wired with a shared cap.
The Yngwie Malmsteen signature Strat has individual tone caps (the tone controls are disconnected on his personal guitars) while the Eric Johnson model and the American Standard Strat have a shared cap.

I really never thought about it until this build. I can see the reason for individual tone caps if you find that each of your pickups (and your ear!) favor a different value cap, but that does cause a problem with both pickups on. Good to know about the "summing" of cap values in this situation.

 

[triple jim]

I understand...
With tone pots cranked the effect of the capacitors is eliminated.
"Useless" because I would never play with the tone pots wide open.
Thanks for making sure I was on the right track!

When they're all the way clockwise, the capacitors are still slightly in the picture, since they're in series with the the pot's full resistance. That's why some guys use no-load pots that break the connection between the wiper and the resistance trace when all the way clockwise. But as you said, if you never play with the pots all the way open, that doesn't matter to you.

 

[Waraxe]

You can use a super switch to assign either tone control to any position. This eliminates the double loading of 2 caps.

You can use a 250k/.047cap for one and a 500k/.022 on the other, then choose which goes where on an hss or hsh guitar.

Of course, the switch isn't an original looking vintage piece.