2. amps-preamps
  3. 162052-34747

suggestion for a SS class AB amp that sounds like a class A ... if such a thing exists

Looking for an amplifier below 2K for my Altec 620A (99 db efficiency). My actual amp is a Sugden A25B, which has 34 watts/chanel in class AB. Although quite musical, it lacks transparency and details. Of course, the best amplifier would be tube or class A but I'm trying to avoid these because of the heat and the electricity bill (my amp is on all day long). My short list include :

  • Audio by Van Alstine Set-120
  • Ayre AX 7e (used)
  • Sugden Mystro (class AB)
  • Benchmark AHB2 (used)

NOTE : please, no class D since I'm not familiar with it (and pretty skeptic too).
128x128alaindexe

Showing 2 responses by audio2design

audio2design
1,351 posts
 
The Benchmark will be by far and away the least class A-sounding, so delete immediately from your list.

That's an interesting comment, since Class-A "sound" is far more influenced by design goals. A low feedback Class-A will have much different distortion products versus Class-A with more feedback, and that is not even taking into account voicing.

If someone makes a transparent sounding Class-A, i.e. neutral, not voiced, and no intentional distortion, then it would be closer to the Benchmark who has very low distortion at low power, somewhat negating any advantage of say Firstwatt and the justification for most ClassA, i.e. removing zero crossing distortion.

audio2design
1,351 posts
 
The Benchmark distortion at low power, i.e. where crossover distortion comes into play is every bit as good and probably better than most Class-A. Same would be true of several new Class D amps.


Nothing repeat nothing! solid state A/B (low bias A) sounds like a 20w> high bias Class-A amp.
As there is no xover distortion in Class-A when the top and bottom transistors switch over from each other, because they’re still both biased into Class-A.



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