Another variable capacitor question, would this work?

[1wahfreak]

So I was going to make my self a small board with a 12 position rotary switch to select between different caps for testing, but then I thought if I could run any two of the 12 positions at time in parallel, I could get a few extra values correct?
My question is how can I get the maximum amount of values out of the 12 positions? Ex, position 1=1uf, position=2uf, position 3=3uf etc. If I can run positions 1 and 2 in parallel I would get 3uf right? But I already have 3uf in position 3. See what I mean?? Here's what I came up with:
Disregarding the x (it was just a spacer), the top row are the values at each postion on the rotary switch, the bottom is the result of position 1 and 2 in parallel, postion 2 and 3 in parallel etc.
1 2 4 5 7 8 10 11 13 14 16 17
x3 6 9 12 15 18 21 24 27 30 34

Also would I have to get 11 seperate switches to be able to turn each parallel pair on and off? Make sense??

[niftydog]

sure, it could work. It'd be complex, possibly expensive, and in the end, how many different options do you need? Like, is 2.5µF going to sound any different to 3µF for instance?

[Seljer]

I always though about using capacitors in pararell with dip switches for this kind of thing for in my wah wah. I think I've seen it done too.

[Paul Perry (Frostwave)]

If you have four single pole switches, and caps of 1, 1, 3, and 5 uF then by putting various combinations of the 4 switches closed to connect the caps in parallel, you can get 1, 2, 3, 4, 5, 6, 7, 8, 9, 10.
And, I've seen that done on old test gear.. but, today I think people would be inclined to go binary! :wink:

[Khas Evets]

You could use a make before break rotary switch and get adjacent caps to combine between detents on the rotary. That would give you 23 posistions.