One of the amps that gets mentioned as a good match for the Polk SDA-2s is the OP's Adcom- I'd be interested in that. I'm currently running off a Yamaha AV RX-679. It advertises 100W/channel but it sounds muddy. I'm still looking, and the spigot still seems to be on...
I have a pair of polk sda2A's that I've owned for over 30 years, I just upgraded them a few years ago new caps, resistors and tweeters. I had an adc gfa555 paired with them for years until it blew up twice, not a bad amp though for the money. I bought a krell ksa 300s a few years ago and it's way better sound than the adcom. I bought a pair of apogee duetta 2 a few years ago also very good sound. It's an addiction for sure.
I have a pair of polk sda2A's that I've owned for over 30 years, I just upgraded them a few years ago new caps, resistors and tweeters. I had an adc gfa555 paired with them for years until it blew up twice, not a bad amp though for the money. I bought a krell ksa 300s a few years ago and it's way better sound than the adcom. I bought a pair of apogee duetta 2 a few years ago also very good sound. It's an addiction for sure.