I had Heros monoblocks at my house. You have to have a Thrax preamp, or at least an Arc preamps and a First Sound preamp would not drive the Heros. The Heros was the closest sounding amp to my SET845 that i have heard. Better bass and top end extension than the SET 845. But the SET845 has a small nudge when it comes to making a violin or stand up bass sound real and in your room. And the SET845 is amazing, even at very low volume levels. The Thrax needed to open up a little before it got great. Not crazy by any means. I never play above 72db. I just don't need to.
