Trimmer caps - unsing them into Fx's

[arma61]

Hi

is a Trimmer cap a variable capacitor ? so, could it be used into an Fx to change, for example, sounds' tones ? looking at all schematics and mods here around often I can ready "change C1 for bass increase, change Cx for beter high respone" and so on.
I saw them at Banzaieffect (link : http://www.banzaieffects.com/Trimmer-Caps-c-463.html).

They have 3 pins would they be used like

pin 1+2 from low value to high value
pin 2+3 from high value to low value

thx for help diyers
Armando

[snoof]

I have wondered about this myself.

edit: D'oh, I should have looked at the values he was referring to...

[nelson]

trimmer caps are in the low pico farad ranges. puting them as input caps you will get fizz adjustable to bumble bee in a very small jam jar. Not really much use to us.

[snoof]

If they came in the...say... 100-500pf range, might they not be handy in a feedback loop for tailoring high freq responce??

[John Lyons]

EDIT: hey, two posts came in while I was typing...

The problem with trimmer caps is that they are large in relation to their capacitance.
The largest cap in the link above is 80pf. Not much use in guitar FX as far as tweaking.
I have seem larger value trimmer caps but they are huge...about the size of a 9v battery if not larger!!

A better way to go is to get a smaller rotary switch with 12 positions (12 caps choices) . Then wire it up with two leads that you can solder in to your circuit in order to test different cap values. You can make up several of these for different parts of the circuit with values such as .001, .002. .003, .01, .02, .05, .1, .2 , .47, 1uf etc.
When you decide on what you like you just de-solder the test rig and insert the cap you choose. Or add in another rotary switch with 3 different caps, or whatever you want.

This can work for resistors as well. It's called a "decade box", 10K, 20K, 30K etc.

John

[arma61]

thx all for reply, I was too precipitous , as soon as I saw them I had that idea and didnìt not check the values available, in deed too little!! thx John for the rotary switch suggestion.

keep diying
Armando

[slacker]

I've seen ones that go from 500-2000pf they would probably be useful in feedback loops or even as coupling caps in high impedance circuits. Unless it's something you're going to want to adjust regularly it's probably easy and cheaper just to try a few different cap values though.

[the_random_hero]

Time for somebody to try a gyrator as an input cap? Actually, I'm not too sure if that's going to work....