Abstract7 made the important distinction between Class A operation and Stereophile's rating system. If you're talking about the Stereophile system, that is defined at the beginning of the April and Oct. component rating issues, and of course in this case, Stereophile defines the classes.
I can strongly recommend the McCormack DNA-0.5 and DNA-1 amps. They operate in A/B mode-- this means that the first few watts are biased into pure class A output. Class A output means that the amp is running "wide open" with only one regulation device. These are both Stereophile Class B amps. The Deluxe models are slightly better. The .5 can be found used for $600-700., and the DNA-1 about $1000. A nice aspect of the McCormack amps is that Steve McCormack of SMc can up-grade them to standards that will easily meet or exceed Stereophile's Class A standards, as your budget allows.
I had a pair of DNA-2DXs up-graded to Revision A, and they are fantastic with great bass and a tube-like mid-range and treble. Good Luck. Craig
I can strongly recommend the McCormack DNA-0.5 and DNA-1 amps. They operate in A/B mode-- this means that the first few watts are biased into pure class A output. Class A output means that the amp is running "wide open" with only one regulation device. These are both Stereophile Class B amps. The Deluxe models are slightly better. The .5 can be found used for $600-700., and the DNA-1 about $1000. A nice aspect of the McCormack amps is that Steve McCormack of SMc can up-grade them to standards that will easily meet or exceed Stereophile's Class A standards, as your budget allows.
I had a pair of DNA-2DXs up-graded to Revision A, and they are fantastic with great bass and a tube-like mid-range and treble. Good Luck. Craig