Can my MC275 power speakers with 91db sensitivity

Jimmy, are you saying that there is a noticeable difference between tube and SS, or are you saying that there is not per se a difference, because a good amp sounds like a good amp. I ask, primarily because if there is no longer an inherent difference in the sound, I will save myself a lot of trouble and go with SS (or maybe not, I love the look of my MC275).

I have no experience with the MC275, but from a technical standpoint I suspect that there is some validity to Polk432's point. The current (Mark VI) version of that amp has a specified damping factor of 22, which is unusually high for a tube amp. Correspondingly, its output impedance is unusually low for a tube amp. That suggests that its design utilizes a greater than average amount of feedback for a tube amp.

Everything else being equal, all of that will shift its sonic character in the direction of being more akin to typical solid state sonics than would otherwise be the case. In numerous ways: A reduction in effects on frequency response flatness resulting from interaction between amplifier output impedance and variation of speaker impedance as a function of frequency; reduced Total Harmonic Distortion (THD); better bass damping than would otherwise be the case; increased Transient Intermodulation Distortion (TIM); a reduction in some lower order harmonic distortion components that tend to be numerically greatest but are relatively inoffensive; and an increase in some higher order harmonic distortion components that tend to be numerically smaller but are more offensive.

Elegal, re your last question, if you want to consider going to a different amplifier you should settle on a choice of speakers first, and then choose an amplifier that will be synergistic with it. Some speakers are designed to sound best with solid state amps, some are designed to sound best with tube amps, and some will do fine either way. The Daedalus speakers I use are an example of a design that will do fine either way. Their output will reflect the intrinsic sonic character of the amplifier that is driving them, but there will be no issues relating to amplifier-speaker interactions with either type of amplifier.

Regards,
-- Al

I believe the original Cremona were rated at 90dB and the Cremona M at 91dB. The article that Al linked to was for the original Cremona. I believe the M are in fact easier to drive than the original Cremona. I have the original Cremona and concur that they are picky about amplifiers. I tried many amps and ended up with a Levinson 432, which does 400 watts are 8 ohm and 800 watts at 4 ohmns.

I would be cautious of your amp with the original Cremona, but it might be OK for the Cremona M. Unfortunately, I do not believe that Atkinson ever measured the M.

Jimmy, I have owned the Mac275 and the MC7270 SS amp. Both were good amps, but the Mac sounds more SS than tube especially when compared to my Cary V12R and CAD120's amps. One thing I really liked about the 275 is that it ran so much cooler than the Carys, just didn't have the warmth.

It can but probably not optimally along the lines related by Al.

That's not to say it won't sound good or meet your needs/expectations, only that you have a good chance of doing better in terms of both volume sans clipping and balanced and clean bass response and lower distortion otherwise as well perhaps to the extent that matters if you become so inclined.

So you can look at these things from the perspective of ideal technical matches that maximize performance, ie the perspective of intelligent "audiophiles" for the most part, or from the perspective of does it sound "good" or "good enough". Improving usually comes at some cost.

So its very much the oft cited "your mileage may vary" type scenario.

If that bothers you, then probably better to seek out different speakers that are more efficient and tube amp friendly in general.

Al's speaker recommendations are good ones. I might toss in Triangle and many Focal/JM Lab speaker models as possibilities.

Even Magneplanars could work very well with a tube amp like that, especially if very high volumes are not a concern.

OHM is another line that is perhaps not as tube amp friendly as some, but offers good value and decent performance with a higher power tube amp.

Adding a powered sub or two and offloading the low bass to that opens up a lot of additional popular speakers choices. That's a popular option for many OHM owners that use tube amps in some cases (some might go sans sub)and also for most any good quality speaker, including SOnus Faber.

Also, most any good quality horn loaded high efficiency speaker (mid 90s db efficient or higher) would be very good technical matches for that amp. There are many very good makers of high efficiency horn loaded speakers out there these days. Take a look at Cathedral speakers out of Virginai for an example of good sounding horns I have heard that can be had for very modest cost.

Electrostatic speakers are another good option to consider if that kind of thing might float your boat.

So basically, there are ways to make that amp work very well indeed with most anything if done right.

Hope that helps.