Send your present Adcom amp to Stan Warren in Oregon; who for less money than you want to spend, will modify your present amp into something you could not afford used in a stock unmodified amp for $350 or even well over $1000. If you do not know of Stan he is the S in PS Audio; then Superfon, and now Supermods.
Actually, after talking to Stan you may find you will want to send him your preamp also. The best way to contact him is to call his home 541-344-3696 --- If you search other threads you will find lots of info about him and his Adcom and DVD player mods.