Solid state design options...


What are the importance (to you) of these design options:

1. Zero Global Feedback
2. Fully Balanced Architectrure
3. Output Class (A vs. A/B)
4. Capacitance / Instantaneous Current Delivery
5. Dampening Factor

Any other ones that should be put into the mix for discussion?

I've been doing some reading where pundants claim these are very important considerations, and some who say they are nothing more than marketing gimmicks.

Thoughts?

I know...You should listen to the amps and let your ears guide you. That is a given, so those replies are not needed.
128x128nrenter
The reason I ask is because some have very stong feelings on this subject. For example, Richard Hardesty (Audio Perfectionist Journal) consistantly claims that the best sounding amps that he has heard are fully-balanced in design w/ no global feedback. However, he doesn't really talk about any other factors of amp design (at least, not yet).

Other reviewers have ranked amps of *very* dissimiar design very closely together. A Clayton M-100 is very different from a McCormack DNA-500, but I have seen them referred to as comparable. Throw tube amps into the equasion, and on paper, things get confusing really quickly. However, the confusion is usually quickly sorted out *if* you are able to do side-by-side listening comparisons (which is generally logistically difficult to do).

Oh...and I apologize for my spelling of 'architecture' in the original post.
Nrenter,

Understand why you posed the question in the 1st place. I agree that it's very hard to discern an amp's sound quality by just looking at the specs & knowing what sort of technology was used to design it. I also agree that the best is to listen to it.

You know, we might be surprised when we open up the M-100 & DNA-500 & place them side-side! It is quite possible that the 2 independent designers used techniques more similar than dis-similar to design their resp. amps! Neither designer provides much info about the techniques used & we have to rely on the IAR journal to ferret these out for us. I suppose that you are referring to that IAR80 article, which I also read with a lot of attention, that put both these amps in the same class.

We just don't know what these designers are putting into their amps esp. if they as tight-lipped as Wilson Shen & Steve McCormack. I read a review on the M-100 amps, which was a reprint of a Bound For Sound review, where I was informed that I should not use high impedance 10-16 Ohm speakers nor should I use a tube pre with the M-100 if I really wanted the amp to sing. J. Peter Moncrieff never mentioned this in his article! So, should I/we append this tit-bit of knowledge on the M-100 to the knowledge gained from the IAR80 article? Don't know......
Ever notice that most amp makers don't publish slew rates. Perhaps because so many are so low. The Hafler 9505 (250w x 2) has a higher slew rate (150 v/us vs. 60 v/us) than any Bryston. The Anthem amps are quite low.