Carver 275 Crimson tube amp --- any feedback appreciated

@steakster 
I know this is an old post but it’s interesting you mentioned tube amps works best with speakers with flat impedance curve. I was told that electrostatics like Martin Logan are best paired with a tube. However these speakers have very volatile impedence and could often drop very low, as I heard. Is there any truth to this? Thanks! I’m trying to decide whether to get my MLs a tube amp, but don’t wanna spending the money if it’s meaningless. 

@steakster thank you for the detailed feedback! You may just have saved me $4,500 going for that Mcintosh 275. 

@whitestix yes I would think so, but despite this logic, I’ve heard from many places, including the ML owners forum that some people swear by tubes with ML. In fact, some older models, it actually says in the manual that they are best driven by “pure class A tubes”. I have had a tube amp before I owned any MLs and I tried it with a pair of Dynaudio Contours and it sounded horrible. I have since been reluctant to go tube again. 

Thanks
Cheers, happy holidays! 

@whitestix

I was lucky to obtain a Mcintosh MC 275 tube amp at ridiculous price. I will test it with the MLs and let you know how it goes. Meanwhile, I found the following explanation from another user which I think really helped me understand why MLs benefit from Tube amps:

"Damping factor and amplifier output impedance are inversely related. Damping factor, as usually defined based on an assumed 8 ohm speaker load, equals output impedance divided into 8 ohms. To the extent that the speaker’s impedance varies with frequency, that output impedance will affect tonal balance, by interacting with the speaker’s impedance vs. frequency variation.

Many electrostatic speakers, for instance, have high impedance at low frequencies, which descend to low values at high frequencies. A solid state amp, having a high damping factor and negligibly small output impedance, will produce LESS bass and MORE treble into that kind of speaker, relative to a tube amp. The tube amp, having a relatively low damping factor/high output impedance, will produce MORE bass and LESS treble into that kind of speaker."

In essence, the Electrostats seem to be the opposite of a normal drive speaker. My understanding is that normal speaker drives have higher impedance as frequencies increase. A solid state that's designed to handle the higher impedance loads at higher frequencies could not "figure out" what to do when the opposite happens. Hence the tube amp comes into rescue.