relay switching

[downweverything]

i was going to make a rackmount acoustic 360 unit and make the footswitches controled via relays with one side of the coil connected to the V+ and then switch the ground on and off the coil via footswitch by sending the ground to the footswitch and then returning it when the switch is activated.  Is running the ground on an extra 20 feet of cable susceptable to noise or other problems as the 360 is pretty power supply sensitive?  if so is there a way to prevent or fix it?

[jplaudio]

If you use a MOSFET or Bipolar to switch the ground side you can control the turn-on time to eliminate pops. You also need to factor the current draw of the relays in your power supply design. Some relays can draw 30-40ma when on. Extending the ground to a footswitch should not introduce noise by itself. If the preamp is extremely sensitive you can always use a separate supply for the relays.

[Joep]

The cable has no influence since it's not carrying any audio signal....

[Transmogrifox]

Yeah, you're pretty safe doing this.  The noise on the 20-ft cable won't accidentally trip your relay or anything, and noise in the relay coil is not likely to get into the signal path unless it is REALLY noisey---then you have other problems.

www.geocities.com/transmogrifox/relay

I have a DPDT single coil latching relay setup at the above site where the Relay doesn't use any current except to switch, and the parts to drive it use minimal current, in case you're interested in more ideas about the relay control side of things.  If you already have a good idea of how you're going to do it, then I guess it's just educational or interesting or whatever.

[downweverything]

cool i wasnt worried about pops or current draw, its not connected to a true bypass or anything and im going to build a large psu, i was only worried about making noise in the ground but you seemed to expell those worries