Tweedman presence control modification

[The Gator]

A friend of mine wants me to make him this circuit. I made it in a 1590BB2 enclosure so I could bring the presents control onto the face and have plenty of room. He wants to see if I can squeeze it all in a 125b enclosure and keep the presents as an external control. I started thinking about the layout and would really like to incorporate a concentric pot for the presence and mid-range to share space. So the question here is would it be better to try and tweak the presents high-pass filter to utilize a 25k pot instead of 10K, or find a way to tweak or modify a concentric potentiometer?
I'm still fuzzy about how the presence control works and what it really does.

Thank you in advance for your input.
~Gator

 

[DGWVI]

The presence pot is just a simple low pass filter, made up of the pot and the 10n (C18) capacitor. It's similar to, but works in reverse of, the Filter pot found on the Proco Rat

Increasing the presence pot to 25k will still give you the stock sounds, but you'll also be able to get a lot darker than stock

 

[The Gator]

That's where I thought about tweaking the cap size to adjust it.

 

[The Gator]

Or perhaps fixed resistor across the 25k pot to get it's "seen" values closer to the original. However that would give it an audio taper affect. Not the worse thing to deal with.

 

[The Gator]

The volume and the treble could be concentrically stacked as they are both 250K. I kinda don't want to mix the volume control with a tone stack control.
I like the idea of the presence and midrange stacked the best. I will have to do some experimenting/testing.

 

[DGWVI]

Or perhaps fixed resistor across the 25k pot to get it's "seen" values closer to the original. However that would give it an audio taper affect. Not the worse thing to deal with.

The volume and the treble could be concentrically stacked as they are both 250K. I kinda don't want to mix the volume control with a tone stack control.
I like the idea of the presence and midrange stacked the best. I will have to do some experimenting/testing.

If you go with the 25k, you could reduce the value of C18.
5.6n would give you a decent approximation of the stock values, and allow the Presence control to get both a little bit darker and brighter than stock

 

[The Gator]

That's funny. I was just doing the same thing. I was going to try 3.9n and see how close that was.