How to tell if an amp is common ground?

[dpowell]

Since I am setting up the office rig to be a place where I can demo different speakers, I want to make sure that the external power amps I buy are common ground so that I can power SDA speakers if I have the opportunity to grab a pair. Is there a list of common ground amps that anyone has compiled or alternatively, how do I find out if an amp is common ground?

[F1nut]

Do you have a VOM?

[dpowell]

If by VOM you mean multimeter then yes, I do have one.

[sophie]

i think you just check for continuity between the negatives on your amp with it turned off and no speakers attached.

Payton

[dpowell]

That's great information for testing amps I already own but what I'd like to do is identify an amp as common ground prior to purchase. Are there certain amps that have that specification? Is there a way to tell from an owner's manual?

[billbillw]

MOST amps are common ground. Non common ground is the exception. For amps that you are going to purchase, just google. Some typical signs of a non-common ground amp might be:
a) monoblocs (obviously)
b) described as dual mono (but usually this ends up still being common ground)
c) have two separate power wires (like the Parasound HCA-3500)

Searching here is always a great resource as well. With all the SDA owners around here, there is a plethora of 1st hand knowledge.