[JMS]

I'm building a PPA and I want to have 2 sets of input RCA jacks. Is it OK to tie together all the input grounds and switch only the signals with a DPDT switch? I intend both inputs to come from home stereo components. Would this cause ground loop problems and such? I'm using the Hammond case with metal faceplates so I'd just tie them through the case. Thanks.

 

[jeffreyj]

Quote:

Originally posted by JMS I'm building a PPA and I want to have 2 sets of input RCA jacks. Is it OK to tie together all the input grounds and switch only the signals with a DPDT switch? I intend both inputs to come from home stereo components. Would this cause ground loop problems and such? I'm using the Hammond case with metal faceplates so I'd just tie them through the case. Thanks.

Generally, it's okay to do this. Indeed, it's done all the time (check out the back of any commercial pre-amp or receiver - I pretty much guarantee all of the ground connections will be tied together).

A ground loop could be formed between the two source devices *if* both of them are grounded. A lot of consumer audio equipment these days is not grounded, so no ground loop can occur. Also, the ground loop noise under most circumstances would only be heard if *both* sources were in use at the same time (ie - mixed together, not switched in one at a time).

So, to make a long post longer, you'll be just fine attaching the RCA jacks directly to the metal chassis.