Audio Research Ref 110 vs. ARC HD220

I sell both and have spent quite a bit of time listening to them side by side with Quatros. My preference is for the REF110, especially on the Quatros where I like to run the REF on the 16 ohm taps. It has plenty of power for very loud listening in all but the largest rooms.

The HD220 is a very good amp but the REF110 is magic.

As an owner of a Reference 110, I would say that if you want the maximum tube “bloom”, musicality, and midrange presence, the REF110 will do a wonderful job, as long as your room is not too large and you do not need to play at extremely loud levels, for long periods. But to realize the full bass dynamics and speed of the Vandersteen 3a sigs, the HD220 can do do a better job. And you can play as loud as you want, for as long as you want, with no output tubes to replace. One other thing: if you often experience some line-voltage variation such as a dip of 8-10 volts or more, then I would also lean toward the HD220. Tube amps need consistent line voltage for both best performance and best service life from the output tubes.
I think, either amp will give you wonderful results, with slightly different sonic “shadings.”
Hope this helps you make your decision.

Tomer

It all depends on the size of your room and the efficiency of your speakers. In my 14x19 room, with Wilson Audio Sophia 2 speakers that are 86dB efficient, I have had absolutely no problems to rise the volume on my Ref 110 to the head banging levels.