Dark switch

BlackhawkRise

Active member
Has anyone considered a "dark switch" on their guitar? For my tone control I use a 0.015uF cap (a little bit smaller than stock) and I feel I can use it effectively for most of the rotation. However, when I am exactly at 0 I prefer the sound of an ever smaller 0.005uF cap.

I'm thinking of splitting the difference by just putting the 5 nF cap on a toggle switch. Has anyone tried this or something similar? Does it pop at all?
 
I've wired my Tele with all 3 variations of the original Leo Fender dark circuit (Broadcaster, Esquire and Tele). They don't pop when you switch to them because there's no active load turning on or off.
 
There's are three dark circuits? I just remember esquire, and two pickup esquire.

Three that I ran across in Fenders.
The Esquire is the best one. It uses two caps and a resistor.
Another version uses 1 cap and 1 resistor.
Another variant uses just a cap, which is almost no different than just turning the tone all the way down.
 
What guitar? If it has 500K pots, you might think about putting a 470K resistor to ground on the toggle switch, instead of a small cap.
Subtle darkening, but it also shifts the resonant peak of your pickups down a bit, just like having a 250K volume pot:.

If you do go with a single cap, you could use one with a trimpot in line, like a tone pot for the very highest treble.
You'd dial the trimpot to taste and close it up - but preserve the option of adjusting it later if you like, without having to rewire anything.
Since it isn't necessarily killing everything above the shelf frequency, you could use a slightly bigger cap, maybe 7-10 nF.

A third option would be something like the Gretsch 'mud switch,' using two different caps and a a center-off DPDT.
Up is one cap, down is the other, center is full frequency response. Modern cap values are a lot more usable than the vintage ones.
And it doesn't have to be all-or-nothing here, either; trimpot(s) to dial in the amount of rolloff could be added to this arrangement.

https://www.premierguitar.com/gear/t...-simulator-mod
 
Last edited:
Has anyone considered a "dark switch" on their guitar? For my tone control I use a 0.015uF cap (a little bit smaller than stock) and I feel I can use it effectively for most of the rotation. However, when I am exactly at 0 I prefer the sound of an ever smaller 0.005uF cap.

I'm thinking of splitting the difference by just putting the 5 nF cap on a toggle switch. Has anyone tried this or something similar? Does it pop at all?

Yep, as mentioned above, Gretsch mounted a 3 positions "mud switch" working on this principle, with 12nF and 39nF caps (if memory serves me) + a neutral center position. Some users like to put lower capacitance components on it.

I've myself a guitar with Filter'Tron's and a push-pull pot enabling / disabling a 3.3nF cap : no it doesn't pop. Switching noise tend to happen with a change in resistive load rather than capacitive load, IME.

BTW, there's really a land to explore in low value capacitors: I started decades ago with 2.2nF caps (before to discover than Bill Lawrence did recommend this value for Hendrix style tones). The 3.3nF cap evoked above makes my Filter'Tron's really close to P.A.F. replicas... On other guitars, I use sometimes lower cap than this (1nF being a good way to obtain a SSL5 voicing from a regular Strat pickup, for instance)... Even a few hundreds picofarad can be handy to tame a bright guitar by simulating the tonal effect of a longer cable. Excellent way to fine-tune the high and high mid ranges by other means than the usual change in pot resistance, IME and IMHO. But I lack of time to keep rambling about that. :-P

EDIT - Just a note: a lower resistance pot squashes the resonant peak of a pickup. A capacitor shifts down its frequency. Not quite the same effect. ;-)
 
Last edited:
I'd try out resistors too, but I do like how capacitors get a little more nasally at exactly 0, it's especially useful with small value caps. I've never used resistors but you may experience some volume loss as well

If you do some research, you'll find that what you're doing is essentially what the PRS sweet switch did. 3.3 nF to 5 nF has the same effect as 70 to 100 feet of cable.
 
Last edited:
Back
Top