i have a pair of sda 2b that i would like to find a better used amp upgrade than the one i have now. i know it has to be common ground (still dont know what that means really) to work well with the sda, but while i am hunting for an amp, is there a way to easily tell if it is common ground or not? do certain brands run common ground, while other brands do not. i have to assume that the integra adm 2.1 amp i am using now is common ground, because it sounds pretty good. but while i have been searching for a used, perhaps vintage amp with some more power, i know if i accidently buy one that is not a common ground, i'll be screwed.
any advise from those with more experience?