Switching between sweep caps in wah pedal. Wich switch to use?

[GuitarDude]

Hey, I want to switch between 0.01, 0.015, 0.022μF, and I've wonder if a 3 way DPDT on on on mini switch will do?? I would have used a 3 way rotary switch but it's not available.  

I want it to be something like this. I haven't found any switches like this on the drawing. BTW the 3 way DPDT switch I've found have 6 legs.

[Paul Marossy]

You're not going to be able to do that with any type of DPDT switch. You're pretty much looking at a rotary switch because of the third capacitor.

[compuwade]

Hey, I want to switch between 0.01, 0.015, 0.022μF, and I've wonder if a 3 way DPDT on on on mini switch will do?? I would have used a 3 way rotary switch but it's not available.  

I want it to be something like this. I haven't found any switches like this on the drawing. BTW the 3 way DPDT switch I've found have 6 legs.

Actually, you can do it with a DPDT switch. But instead of switching between different caps, you can add caps in parallel to get close to the values you want. For instance, you can start with the 1st 10n cap, then use the switch to add a 4.7n cap to make 14.7n, then in the next position you could use a 10n or 15n cap to add to the 10n cap to make either 20n or 25n. That way you will still be close to the values you want but without having to use a rotary swtich.

Just a thought!

[ubersam]

you can even do it with an on-off-on SPDT.

[KazooMan]

I wanted to do a similar cap switching mod for a Small Clone Chorus and a Wah Pedal kit from GGG.  

Small Bear sells a very compact SP6T rotary switch designed for PCB mounting.  The main issue for the switch is that the pins have a very strange layout with some duplication.  I designed a small PCB to mount the switch and the caps.  They posted a picture of the board in use as well as the layout for transfer.  

http://www.smallbearelec.com/Detail.bok?no=581

Here are the photos:






The pad labelled R is the rotor.  The end pad on the long leg to the right is the other connection.  Just hook these up to the board where your original capacitor should be.


Dick Thomas

[GuitarDude]

Thanks for answering I think I'll go with the parallel idea from compuwade because the values is close enough and I haven't found any stores that sells rotary switches in Norway.

[Paul Marossy]

I thought of a DPDT switch at first, but that doesn't give you three seperate values like what was presented. I suppose a compromise could be a on-off-on DPDT switch that parallels cap values. But it would have to be wired differently than the picture shows...

[Gus]

I have used dip switches with the caps values set up in a something like a  binary fashion the 2nd is about x2 the first and the 3rd is about X4 the first etc.  The cap values add in ||