Was using my AGD Audion MKIIs.
Actually, I now have ARC Ref 80S. Very similar to George’s Ref 160S.
And between the AGDs and the ARC I thoroughly enjoyed Ralph’s Class Ds.
The AGDs are beautiful sounding and very musical. However, Ralph’s easily surpassed them in musicality and, especially, in bass. They are much more substantial in many major ways.
At 3 times the price, the Ref 80S takes things to a new level. Contrary to Ralph’s position that the amps are now on “life support”, the tube magic of the Ref 80S makes it stand out in quite a spectacular way. Mostly, the ARC brings “life” without any need for “support”. A good example of “you get what you pay for”.