RELAY just after INPUT JACK (tube preamp+ss pedals)

[richon]

I plan to build a "crazy" preamp

channel one: clean -to-plexi/800 all tube
channel two: SS pedal (overdrive) before the tube preamp (all inside the same box)
channel three: SS pedal (Distortion)

the main idea is to switch between going direct to the tube preamp, or  just after the input jack put a relay to send the sound to any of the SS pedals and back to the tube preamp.

would this make some bad sounds (relays poping) or any damage to any of the parts?
PS: as for damage I almoust certain that NOT....  as for the relay pop...   

[Zapp Brannigan]

I think you should study Soldano GTO schematics. This pedal has relay after input jack, which drags fx input to ground while bypass is on. Your task is similar - use relay to mute channels when they are bypassed. To avoid relay popping insert diode between relay's driving lugs (watch GTO schematics too). I would also recommend you to use 3PDT switch in relay on|off circuit (if you need LED indication use free group of contacts, that's why 3PDT), it diminishes popping too when you break relays driving voltage on both lugs simultaneously, ... well, at least I didn't notice any popping. I hope the idea is clear, and sorry for my English, it's poor, I know.

[tubelectron]

Hi & beware :

some relays are unable to reliably pass or cut frankly very low signal currents, despite their look or specs, so it may result in bad or no contact and clicks noises... Choose specially designed low signal relays AND anyway make a trial first to see if the relay works well for this audio application. Moreover, the reliability of the contacts may be questionnable in the time. I have had bad experiences in the past...

A+!