For a good match, why not the Anthem STR amp? I have found that sometimes mating amp and preamp from the same company can give synergy.
Another choice of a well-built amp that will last a long time is the Bryston 4B3. I am using that with the STR preamp and think it’s a great match.
Another choice of a well-built amp that will last a long time is the Bryston 4B3. I am using that with the STR preamp and think it’s a great match.