External standby switch: why so noisy?

[rockhorst]

Being noob, I have planned a few very simple quick projects, to get some basic practice.
First thing is really the simplest of simplest: an on/off switch to put between my guitar and amp to facilitate fast guitar switching without having to go over to the amp to put it on standby. So basically it's two mono jack input and an on/off switch that either connects them or sends the signal to the ground.

In principle the thing is working, but when on 'standby' it produces a lot of unpleasant (white-ish) noise (wich especially becomes apparent when turning up the volume). Any ideas where I messed up? I was thinking maybe putting a resistor in the ground circuit could help? This is just a guess though. Another possible explanation that I came up with is that a jack cable will always produce some noise when not connected, possibly due to voltage differences? I really would like to solve this (if at all possible) before I move on to more complicated things, cuz it seems quite a fundamental problem.

And a little picture (black = ground)


Tx in advance

[rockhorst]

I hope you don't mind me bumping this question. I tried about every earthing possibility, made sure I'm not making contact with aluminum casing etc. etc...but I keep getting a lot of noise being generated when I open the switch...No suggestions anybody?

[R.G.]

I'd check to see if the signal is actually being shunted to ground when the switch is flipped.

The symptoms you describe is similar to what I'd expect if you had opened the signal line, not shorted it to ground.

Here's another experiment to try. Take a guitar cord and a bare wire, and wrap the wire around the tip and sleeve of one end of the cord. Then plug the non-wired end into your amp. Does the amp make this noise then? If so, you haven't done anything wrong in the switch, it's something in your amp.

[rockhorst]

Hey, I guess it is something in my amp then 
Hope you don't mind, but I'm gonna type you a p.m. R.G...