Adding "on/off" switch to Jensen 1x4 guitar splitter?

I built the Jensen 1x4 guitar splitter for a friend last Christmas.  Here's the schematic:  http://www.jensentransformers.com/as/as014.pdf

He's now asking me if I can add an "on/off" switch to each of the isolated outputs to allow him to turn off any outputs so he can audition amps one by one with only the flip of switches on the faceplate of the splitter.  My initial thought was to simply disconnect the circuit leads to the 1/4" output jacks, but then I realized that in practice this would be just like pulling the cable out of the splitter, but leaving it in the amp, which would result in horrendous noise just as if the guitar had been unplugged from the activce amp. 

I know "bypass" switches on tube amps work by cutting the B+ voltage to the tubes, but how would I make an effective 'kill' switch on the splitter itself that would result in only the self-noise of the amp? 

It seems to me that the "off" switch could simply short the leads at the 1/4" connector, which would definitely kill the signal, but would having the length of cable still connected affect the noise somehow, even though the signal conductor is shorted to ground?

Sorry for the goofy question.  I'm not that familiar with guitar amp-related stuff.

Thanks for your help!

Peace,

JC

Hmmm how to do it without any logic kind of switching ?
kind of like a solo switch on a console , something multi poled
to ground first whever the gtr was coming from ?

if it doesn't have to be " footswitchable " in real time , then
a rotary switch with make before break , double pole ?

rascalseven said:

It seems to me that the "off" switch could simply short the leads at the 1/4" connector, which would definitely kill the signal, but would having the length of cable still connected affect the noise somehow, even though the signal conductor is shorted to ground?

Click to expand...

A lot of guitar amps have switching jacks on the inputs so that with no cable inserted, the tip is tied to ground.  Having a cable connected between the amp and the splitter box (and subsequently killing the signal by shorting it to output signal ground at the splitter box) probably isn't going to induce any more noise than not having a cable inserted at all, unless the cable is running next to some high current AC lines or wrapped around a radio antenna or something.  If that's the case, you'd hear that noise when the kill switch wasn't thrown anyway.

That's what I thought.  Thanks!

JC