Power: Good or Bad

I agree that if everything else is held constant, like your speaker example, that a low-powered amp would likely sound better. Especially in the case of speakers with high voltage sensitivity and/or a benign impedance curve. But even this is not always true. For instance, some manufacturers use better quality parts in their more expensive offerings. Also, even in this instance, it is arguable what sounds better. Some listeners may like the improved bass or dynamics that the higher-powered amp produces, while others like the tonal purity of the lower-powered amp. I spent a lot of time with some very efficient Von Schweikert speakers at a dealer trying to decide on which Cary SET tube amp to mate with the speakers, ones that used 211's, ones with 300B's, and ones with 2A3's. Even then, the sound was a tradeoff, and even a push-pull BAT tube amp had its merits. I might buy that your speakers may sound better with lower-powered amplification, but in the real world with varying amp manufacturers, associated electronics, speakers, rooms, musical tastes, and sonic preferences, IMO it is too big a generalization. BTW, one of the reasons speaker manufacturers design speakers with low sensitivities and/or tough impedance curves is bass response and also to get a certain tonal balance. But I have been most impressed with many different types of setups, inefficient speakers with big SS amps and very efficient speakers with low-powered amps. Right now I am in the moderately efficient speakers camp with a very powerful SS amp, which is by far the best amp I have heard.

Rlawry:

The SET amp threw a bigger soundstage, was more warm and full, and had a more ripe bass. The big SS amp had far more bass impact, was more transparent and detailed, and had better dynamics. Which was better?

Actually, you answered the question yself: the ss amp was better, in THAT particular APPLICATION.
The amp-spkr interfacing you described indicates this.
As you note, one may or may not prefer the result -- i.e. the chosen compromise -- but that's another story. Cheers

Thank you for your responses. It is really interesting. I'm starting to see more clearly the primary importance of system matching and synergy, and the diffuculty we sometimes get into when we ask "What is the best this or that?", independent of system context - where the amp/speaker interface is so important. The answer is clearly very system dependent. This make answering these types of ("best")questions more difficult, more artful, but that is the nature of the hobby and speaks to the value of a good dealer, trusted audiogon members, etc that are aware that great sound (and tastes may differ) requires more thought and effort then buying the "best" this or the "best" that. A pleasure hearing your thoughts.

Great summation, Pubul57...system synergy is really the key to enjoying music. Personally, I have moved away from high powered amplification now, and cannot tell you how wonderful my little Audion PX25 sounds...producing 8 watts...with Audio Note Lexus speaker cables and an Acrotec interconnect into an old Rotel 965LE with D.I.T.B. as the processor, and Reyanud MK II speakers. The system works together (trial and error) as a unit and produces music...the system is organic, and is not to be viewed as a set of components. Yes, I have components that are rated "Class A", and I am selling them off now, and keeping this little system.

I think the understanding of the relationship between a chosen speaker and the amplfier necessary to make the best of it is the key equipment relationship and the one that a good dealer could be most helpful in educating the customer. There is such a preconcieved prejudice towards thinking that bigger is better, and coincidentally more watts cost more, that we often go down that road without really understanding that you don't need more power than you need, and that lower power is always simpler and purer, and "better" if adequate to drive the speaker. Of course, some speakers won't be satisified with low to medium power, and you then you do need more power, indeed a lower power amp will not satisfy, will not be adequate. I therefore lean towards relatively sensitive speakers, with high and "flat" impedances to work best with tubes, and that can be driven by a wider variety of low (20 watts) to mid (60 watt) amplfiers.