I guess it depends what you like. ASR is extremely quiet and a bit warm. If you want sound stage, you might want to try tubes. Those speakers are pretty easy to drive, so a mid-power tube amp like an EAR or conrad-johnson might be just the ticket. Alternatively, Vitus Audio's Reference line might be good to check out (and were it me, that's where I'd look). DarTZeel is apparently very nice, especially for loudspeakers that are an easy load, but I know some folks that have "upgraded" from that to BMC (and onward, but that's another thing).