3 guitar 1 Amp need a switcher

[griffin]

Ok
3 Guitars 1 amp. I need a switch that will i can select which guitar I want.
An A,B,C,Y Box.
3 foot switchers 3 leds and 1 box.
But the trick is that I need to be able to only select 1 at a time.
So if A is on and I switch to C, it will switch off A automatically, or if I switch to B etc..
So no more then 1 input selectable at any time.
Is this possible?

[Cabezahead]

I would imagine there's a single switch that'll do that for ya...  3p3t or something like that?

Are you doing this stuff mid song?  Is it really too big a hassel to turn one off and the otherone on?

-CH

[NaBo]

Well I don't think theres a *simple* way of doing this using STOMP switches...  you can see the parallelyzer over at //www.generalguitargadgets.com, specifically the mixing stage for some good info and diagrams regarding this type of switching using DPDT stomps.  But this doesn't automatically turn off other channels, etc...  and that many switches would likely be too clumsy.

You're not likely to find a stomp switch that can do all the switching mechanically (3 throws), and if you do it would likely be ridiculously expensive.  I highly doubt they exist becauuuuse...  Relay/digital logic switching is possible........ but i wouldnt bother with the headache and power consumption of that... becauuuuuse--- For your purposes, are stomp switches really necessary?  If you're going to be physically switching guitars, you might as well take the second to reach down and fiddle with an sp3t rotary or slide switch... which would be the simplest-easiest-smallest-cheapest way of accomplishing the type of switching you described.

[Mike Burgundy]

if you really want the siwtching to be exclusive (selecting A will automatically switch everything else off no matter what's on, etc) you'll need some logic and relays or MOSFET switching. It is very possible though.
I reckon the simplest implementation is a buffered 3-in, 1-out mixer with all three inputs connceted. If you hook up a MOSFET from signal to ground (drain-source) on every input before the buffer, you can use that to clamp that input to ground: it's silent. If the MOSFET is off, it's resistance is megaOhms to tens of megaOhms - no problem with loading for the channel you want to use.
Some switching logic that clamps to ground for "channel ON" and to a couple of volts for "channel OFF" and a handful of BC170's should work.
This might be a good place to use those actuator switches that Smallbear sells. Also, have a look at Jack Orman's simple mixer at www.muzique.com

[R.G.]

There's a simple way of doing this with stomp switches.

Go to GEO. Look at "A Programmable Footswitch System"  (http://geofex.com/Article_Folders/fxswitchr/fxswitchr.htm)
and go down to Figure 7. You can use a 74C373 logic chip as shown to get a one-of-six switch, or, leaving off three of the footswitches, one of three.

Then you use the outputs of the 373 to drive a single NPN transistor driver to turn the relay on and off. A good circuit to do that is shown in "A Latching Relay Bypass Circuit" (http://geofex.com/FX_images/ltchrly.gif). You use the circuit of the 10K resistor, NPN transistor, and diodes to drive the relay. Note that used in this way, the relay must be a non-latching type, not a latching type as shown in this last circuit.

The 74C373 has special characteristics that make this work, do not substitute a 74HC373, 74HCT373, 74373, etc, which do the same logic function, but do not latch properly in this application.

Finally, if you use 3PDT relays, the relays themselves can be hooked up to do a one-of-N latching function. This involves playing games with partial hold-in currents to the coils, but works beautifully.

[Satch12879]

Check out the Lehle 3@1

[bwanasonic]

I always found the easiest and most failsafe way of doing this was just to mute the cable (volume pedal) and just switch guitars. And I've been known to have few guitars onstage... :wink:

Kerry M