I've had both in my system for direct comparison. The Ref 210s provided slightly more expansive and deeper soundstage and (my guess is) should provide more power at fairly extreme listening levels.
My test did not go beyond 95 dbs at my listening position.
But in all other respects including grip, palpability and an overall more realistic and natural presentation, the Ref 150 was vastly superior. The slight percentage loss re soundstage was hardly noticeable as that characteristic is provided in spades by all ARC tube amps. Furthermore the low and mid bass was better delineated and more palpable with the Ref 150.
My feeling on ARC gear is that up until the Ref 150/250 series amps, the overall presentation was wonderful and well worth the price of admission, albeit a bit too much on the side of light and airy---diaphanous
I think that problem has been substantially mitigated if not eliminated in the 150/250 series, especially so with KT 120s and now KT 150s.
My test did not go beyond 95 dbs at my listening position.
But in all other respects including grip, palpability and an overall more realistic and natural presentation, the Ref 150 was vastly superior. The slight percentage loss re soundstage was hardly noticeable as that characteristic is provided in spades by all ARC tube amps. Furthermore the low and mid bass was better delineated and more palpable with the Ref 150.
My feeling on ARC gear is that up until the Ref 150/250 series amps, the overall presentation was wonderful and well worth the price of admission, albeit a bit too much on the side of light and airy---diaphanous
I think that problem has been substantially mitigated if not eliminated in the 150/250 series, especially so with KT 120s and now KT 150s.