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Passive Switch Box Schematics

I've tidied up my collection of passive switch box schematics and pasted them all together, hopefully these may be of use to people who want to have a bash at wielding a soldering iron and put one of these incredibly useful little boxes together themselves.

Passive Switch Wiring
9V battery powers the LED indicators thru a 2k resistor
Uses combinations of 3PDT and DPDT switches
X-grounding for noise suppression where appropriate
Where not indicated, jackplug earths are grounded out together

1. A/B switch allows switching between 2 inputs into one output (eg: switch between 2 guitars in a gig without having to unplug) or use in reverse with one input switching between 2 outputs, eg: 1 guitar into either of 2 amps or amp/tuner, or select pedal chain or bypass for example.

2. A/B/Y switch allows AND/OR config: one guitar into either amp A OR amp B OR both at same time.
Note: Can be used in reverse as A/B box but not recommended for 2 inputs simultaneously into one amp - guitars will interfere and cause hum.

3. A/B+X/Y switch allows A or B choice on input and X or Y choice on output, for example, choose one of 2 guitars on stage into one of 2 different amps, 1 of 2 guitars into either amp or tuner (will mute amp)

4. A/B/C switch allows one of 3 guitars into 1 amp or in reverse, 1 input into either of 2 amps or a tuner for example. Switch 1 chooses between A and (B or C). Switch 2 chooses either B or C.

5. Feedback/Loop switch selects to either bypass or route signal thru an effects box with option to blend some of the 'wet' signal back into the effect loop (level set by 250k pot) or leave it 'one-pass'.

switching.jpg
 
I totally forgot.

I have a switch and box.. it's probably a single on/off (spst?).. I've delayed assembling this as I'm sure I just can't switch the hot on/off without hearing a pop.

It would be cool to have an LED status.. not necessary.

I do plan on doing dual on one side .. this would allow me to patch in a drum machine or iPod if necessary.

Sincere thanks.. I will post results.

AB SWITCH..
I'm not that elecytronically bright.. as this looks, we're using one of the posts on the switch to fire the LED.. correct? I could eliminate this and just use a pigtale type switch --- correct? Any tips on how to minimize a "pop"
 
the third row of lugs on the 3pdt switches are for the LED indicators. You can dispense with them if you don't want LED's, but jeez, who doesn't want LED's? LED's are great!
The stereo jack is wired to switch the battery in and out of the circuit to power the LED's. If you don't want batteries or lights you can use a mono.
 
Thanks Al.

Funny thing is we own a little company.. we had a machine come in with a foot switch.. found a small box.. thought why not.

So to clarify.

If I just switch the hot.. it shouldn't "pop" or is there some type of noise supressor I should concern myself with.

T.

Thanks again.. this has been on the back of my mind for a month or so. I play a gig where we get up and down.. I do not like to turn on/off amps .. switching off the input would be smart.
 
So, someone just asked me to build them an a/b box. I said no problem, but then they asked if it could have three inputs, I said no problem. But I know sometimes he is going to want to play through B and C, no A. How can this be done?
 
I don't see why the A/B switch wouldn't work... just leave "B" leading to nowhere.

I put those switches on my e basses. on= wired regular off= to ground.

I am gonna build a passive A/B box with 2 switches- one for mute. Also going to put stacked volume/tone knobs on each. This will be for balancing upright/electric through one amp.

I am going to build it for 2 reasons- 1. I can't find one to buy anywhere; and 2. I want it totally passive-
 
How would I build a combination Loop-A/B/Y? Basically it would have an effects loop, and I could select to either output just the loop, just the bypass, or a mixture of both combined that is controlled by a pot. Or is that what the loop above does? I'm just getting into building stompboxes and am a little confused.