Wiring a Pot with a DPDT switch...

Started by liquids, November 20, 2008, 01:47:08 PM

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liquids

Hello,

I'm still really new at this and have really enjoyed prototyping a few things on breadboards, and am excited to say that I've finally started soldering stuff up!  Since I don't have the space or tools at home to drill my own boxes, I'm generally going to need to purchase pre-drilled boxes for my pedals.  Without breaking the bank and sticking to the  reasonably priced pre-drilled boxes (GGG, PPP), the options end up a little limited in knob count, adding holes for switches, etc. 

Despite this , I'm a tweak-aholic and sometimes want a few extra options on board, so my though has been to use these boxes but to integrate some 16mm pots that have DPDT pull-out knobs like the ones at small bear: http://www.smallbearelec.com/Detail.bok?no=619

I've got a BSIAB 2 board I'm putting together and I have the values I like the most all figured out.  I probably wont have the board finished till the weekend, and for now I plan on keeping the DPDT switches out of the equation, as there's enough that could go wrong with a first build.  But once I get it soldered, debugged, and working, I plan on trying to add in some mods using the the switches.  My issue is, I'm not sure I really know how to wire them up correctly!  In the end think it would be fun and useful to find a way to switch between two different resistor values for R10--to affect the range of gain--and switch in/out one or both of the LPF, i.e. C14, for example on this particular circuit.

Here's my current thought process....  I would solder wire in the pads on each side of the board in place of R10, and connect those wires to each side of the the center pair of tabs on the DPDT switch.  Across the top pair of tabs I would solder one resistor value, and across the other pair I would solder the other resistor value, meaning when I switch the pot in/out I will choose between one or the other resistor's value going to ground, as opposed to adding them in parallel or series.  Is that correct?

For switching C14 in/out...  Again, I would solder wires in the pads for each side of C14 on the board, and connect those wires to each side of the center pair of tabs on the DPDT switch.   I would wire the cap from one tab to the other on the bottom pair of tabs.  On the top I would leave the tabs empty, which would be the same as removing the cap from the circuit. Is that correct?

If not, what would be the proper way to wire these switches?  Also, any tips for making this kind of modification less frustrating and not so messy inside the box?

Thanks from a beginner.   :icon_smile:
Breadboard it!

jacobyjd

Your description sounds like you'd be wiring them right. There's really no way I can think of to reduce the extra spaghetti that parts-switching generates...you could twist your wires if that's your style--it doesn't really matter which wire goes to either pole (unless the cap is polarized). That makes things look a little neater to some people :)

I've considered using push-pull pots as kind of a sleeper tweak mod on my simpler builds--I've just never gotten around to trying it. Cool idea though :)
Warsaw, Indiana's poetic love rock band: http://www.bellwethermusic.net