To drive your amp with a phono preamp it would have to have enough voltage and gain with a volume control. This is the kind of phono preamp you would need to drive your amp directly. BTW,my friend uses that EAR with no preamp. I tried my Quicksilver phono preamp going into my amp and I could not get any volume. If you get a phono preamp you would plug it into any aux input on the Adcom!
http://www.needledoctor.com/EAR-834P-Phono-Preamp?sc=2&category=35450
http://www.needledoctor.com/EAR-834P-Phono-Preamp?sc=2&category=35450