Bob Carver "Black Beauty 305" or the E.A.R. 890

With the Magico S5 you're REALLY going to want more power than 70 Watts. They're nice speakers and I've heard them do OK with 180 Watt/ch tube amp on the 4 ohm taps, but when mistakenly moved to the 8 ohm tap (reducing power and increasing distortion, i.e. sort-of simulating a lower powered tube amp), the result was awful.

The Carver 305 should have enough power to do just fine. However, the S5's 89dB rating can be deceiving in that it's a sensitivity spec and these are 4 ohm speakers; tube amps will only yield 86dB/Watt here. A high-end SS amps will typically "double" (not really, but close) its power into 4 ohms; thus, the nature of this speaker works with SS and against tubes. I'm sure they were designed with high-power SS in mind. Also from what I heard, they'd probably benefit from higher damping factors as well -- again, lending themselves to high-power SS.

In summary, with S5 I think you'd have a bad match with the EAR and a potentially good-to-great match with the Carver, but other (SS) options may be even better. I'm a tubes guy, so it takes a LOT for me to consider SS options over tubes, but I think the S5 may be one of those special cases.

Also, your 24' x 27' room would be considered quite large! Indeed, I would suggest you require quite a healthy dose of power unless you *always* listen at very low volume levels. Really, your power needs are dictated more by the peak/crest levels you hit rather than your average levels -- these peaks can shoot up surprisingly high on high dynamic range material (classical), but they're typically very close to the average level on highly compressed rock/pop recordings.

+3dB is (almost exactly) twice the acoustic energy -- that's not subjective. How much "louder" it sounds to a person is somewhat subjective. Some folks prescribe that +10dB constitutes a doubling in perceived volume, others say +6dB; personally I find even +3dB to be quite significant, and +10dB sounds a lot more than just twice as loud.

I didn't put it in the title because it is a second discussion... but, audio guy I'm working with suggestion was a choice between the Carver and the Bryston 28BSST2 (at 1000 wpc). I have a tube pre-amp so there would still be tubes in the system. I love the sound of tube amps -- if I go that root for more power I'll have to listen for a while before I choose.

Yeah, I'm with you there. I'd have to hear the SS amp first, and I'd be very wary of amps with a reputation of being analytical or bright (a reputation that seems to follow the Bryson amps to some degree). I owned some Parasound JC1 monos a while ago that had a very nice sonic balance for SS, and with plenty of power on tap into 4 ohms.