We have XPA-1s driving Thiel 3.7s. Upstream, a Bryston BCD-1 feeds an Audio Research REF-5.
XPA-1 input gain is very high at 32db and the 3.7 has sensitivity at 90db and yet the speakers are dead silent when REF-5 is muted. With mute off, there is a very soft barely audible tube rush (1-inch from the drivers) normal with tube gear.
The amplifiers share a dedicated 20A socket. Other components share a Belkin 12-outlet surge protector plugged into a dedicated 15A. There are no conditioning of any sort.
XPA-1 is neutral. Change of cables and components result in corresponding change in sound. Differences in recording qualities show through planly. Bad ones sound bad while good ones are magical with the REF-5 in total control.
XPA-1's performance level competes against the big boys like the ARC 610T. Where the 610T stuns with their uncanny realism, the XPA-1s are, by my estimates, 80-85% that of the 610T. The question is whether the last 15-20% is important enough to worth the extra clams. This is a personal decision.
Before the Emotivas, I tried a pair of Bryston 7B SST2 with our set-up and while these are nice amplifiers, they do not match well and not to my taste.
The 7B SST2 (with new power) came across very polite and somewhat recessed. Details were sometimes hard to hear. Adjusting the voltage in the back was unsatisfactory. At lower gain, it became overly polite and analytical and cold. At higher gain, it got "hard" and tough on our ears.
I do not believe the 7BSST2s are at "fault". They are just not appropriate for the speakers and the linestage and my taste. The Thiel 3.7s demand a lot of raw power even at low decibel to sound their best and the 7BSST2 are not a good match.
Cheers!
