Recommend A Capacitor

[Drak]

That will go on a P/P volume pot on/off switch.

No tone pot, just a cap wired to the switch, either engaged or not.

Something that would give me the sound of a tone pot on say 7, just rounding over the top end.

.01uF? .002uF? .003uF?

[Lucius Paisley]

I'll just get this out of the way...

[Spaghetti Bolo]

If you want that exact sound then you need to use a cap and series-connected resistor. You could use a trimpot to dial it in exactly how you want it.

[hamerfan]

I used to have a very small cap, just to have a smoother distorted sound. Was like 120pF = .0012uF

[GuitarStv]

That will go on a P/P volume pot on/off switch.

No tone pot, just a cap wired to the switch, either engaged or not.

Something that would give me the sound of a tone pot on say 7, just rounding over the top end.

.01uF? .002uF? .003uF?

Why not measure the value of a tone pot rolled to 7, then wire a fixed resistor with a capacitor . . . the same way you would normally do a tone pot? (Or even better, use a mini tone pot in the electronics cavity so if you want in the future you can just alter the tone roll off?) Then you just use a .022 or whatever cap you normally like.

[GuitarDoc]

What's the problem with just turning your tone pot to 7 to get the sound of a tone pot turned to 7? Does your guitar not already have a tone pot...only a vol pot? Why have a p/p on the vol pot to act as an on/off? Just turn the vol all the way down to "turn it off". Then you could add a 330k resistor and a .022uf cap to one end of the p/p. Those values are a rough approximation, but you could do some measurements and calculations to come up with the exact values that would work for you.

[Drak]

What's the problem with just turning your tone pot to 7 to get the sound of a tone pot turned to 7? Does your guitar not already have a tone pot...only a vol pot? Why have a p/p on the vol pot to act as an on/off? Just turn the vol all the way down to "turn it off". Then you could add a 330k resistor and a .022uf cap to one end of the p/p. Those values are a rough approximation, but you could do some measurements and calculations to come up with the exact values that would work for you.

No, the guitar does not have a tone pot, nor will it have one, but I want a 'darkener' switch, like a tone pot turned down to 7.
I figured if someone has done it before me, they'd get me to at least a good place to start.
So I need a resistor and cap, got it.

Having a mini-pot in the cavity is an interesting solution, thanks for that.

[jeremy]

i use a .01 cap for a dark setting on an esquire, no resistor, and its way more than you want. id start with maybe .005

[Clint 55]

6.8nf is the cutoff that still sounds bassy, so you would want to go below that for only a cap. When you get as low as 100pf, it starts to barely just lop off the highs. However, I think a regular value cap plus a resistor is the way to go.

[ehdwuld]

Get a box of these

https://www.amazon.com/dp/B07WGHCMZC

Attach the standard .22 cap

Set to seven and bury it in the cavity
Wrap a bit of tape on it so it doesn't do anything unexpected
Clip off the extra leg

Then at some poin dial it to 8 or 6 if you want
Why be stuck with seven

My next mod is putting a piezo bridge and volume in a guitar that only has two holes for knobs

this is my plan since i rarely jank with the tone knobs anyways

[eclecticsynergy]

A lot depends on the pickup. For a bright PAF type, smoothing the harsh with a really small cap - no resistor - is a totally viable option.
If the pickup is something beefier (which seems pretty likely in a one-knob guitar) trimpot or measure+resistor is the way to go.
Then it's a question of choosing a cap that'll affect your upper mids too, or roll off just the highs.
Caps are cheap; it might be worth trying a few and picking your favorite.
But .022uF is the value most often matched with humbuckers.

I concur with the others that a trimpot would be the better choice here since you can fine-tune later if desired.
Gear often behaves differently at battle volume than it does at home.
Also our tastes can change over time.

If it's a rear rout, you can leave the cavity uncovered and tweak the trimpot at rehearsals until it's dialed in exactly how you like it.

[Drak]

You guys gave me an idea...I could probably drill and mount one of those mini-pots to the rear control cavity cover itself.
All my covers are shielded and connected to the interior shielding so they're grounded already.
Might do it, might not, but thanks for the ideas, the neural pathways are warming up.

I wonder if you could no-load one of those little bastids...

[ehdwuld]

If you are going to tweak it enough to drill a hole in your cover, drill a hole in the face and put a tone control on it.

As far as no load Make the volume a push pull and switch it out of circuit