No Load Pot for Volume?

[Chaos]

Re: No Load Pot for Volume?

(1) Yes, there is a break in the connection between 9 and 10 on a no load pot.
As Artie stated, you need minimum three connections to make a voltage divider
(See Artie’s schematic 1,2,5 or 6. A no load pot is schematic 3 or 4)

(2) Yes and no. The output is passing through both the TBR and the lower half of the pot. Using the hydraulics analogy again, the TBR is acting like a shunt to route around the break you’ve created in the first pipe.

(3) For all practical purposes, yes. There will be a small loss due to heat caused by the additional resistance in the 500k pot and a different degree of loading, but the effects are minor in the scheme of things.

 

[Artie]

Re: No Load Pot for Volume?

(3) For all practical purposes, yes. There will be a small loss due to heat caused by the additional resistance in the 500k pot and a different degree of loading, but the effects are minor in the scheme of things.

I would disagree with this, but only slightly.

If we consider "normal" volume control wiring, a 500k volume pot dialed down to 250k, still presents a 500k load to the pup. A 250k presents a 250k load to the pup. There is a slight difference in tone due to this difference in load. Its the reason we talk about 250k vs 500k pots all the time.

 

[MattPete]

Re: No Load Pot for Volume?

Cripes, after looking at this, I get it now:

In my head, I was visualizing it working like this:

In my hydraulic model, the ground acted as a black hole that sucked all of the signal away. So, adding resistance at R2 kept the signal from being sucked to ground.


Now I need to think about the implication of all of this (and whip out a soldering iron to see what a normal 250k pot sounds like).

 

[MattPete]

Re: No Load Pot for Volume?

Thanks guys! I just installed a normal 250k volume pot, and my strat sounds much better!

 

[Jacew]

Re: No Load Pot for Volume?

I was also scheming a way to use no-load pot for volume. It doesn't work with a regular no-load pot, but you can DIY it from a dual pot.

First open the pot and scratch off the graphite at position 10 of the wiper of taper A. Then wire pot as follows:

IN (eg. from pickup switch) to lug 2 (wiper) of taper B. OUT (eg. to output jack) to lug 1 of taper B. Then connect lug 2 of taper B and lug 2 of taper A (wiper to wiper) and ground to lug 3 of taper A.