Why do you think the Benchmark amp has similar HF noise? Because they talk about using a "switching power supply"? I admit that I can't tell what they're talking about, since they discuss Class H characteristics in their literature (to the point of that being responsible for the H in the product name), which implies output power rail voltage manipulation, and then they discuss a switching power supply (implying some sort of Class D-like operation). Of course, they are the same guys discussing "inter-sample overs" WRT to digital recording, so I do have some skepticism about Benchmark's literature.
Wow, you don't miss a thing do you? I thought I deleted my last sentence soon enough but you still manage to quote me, probably right before I clicked "save".
I wrote that in because somehow I initially thought the AHB2 had the switching power supply as well. Shortly after my post I thought there's no way someone like JA would miss something like that so I did another quick read on the review, and then I realized Kal described the power supply as below:
"Tied to the AAA technology is a system of class-H power-supply rails that track power demands in order to increase amplifier efficiency without the penalty of added distortion; the power supply itself is a regulated switch-mode type that uses resonant switching, claimed by Benchmark to reduce noise.
Since I know little about that kind of power supply I decided to delete my comment. Unfortunately it is now in your quote but that's my own fault. I don't like the way they generalized the crossover distortion issue with class AB amps, but to give them the credit, at least they added the word "traditional". I take it their subtle way of hinting that not all class AB amps, just "traditional" class AB amps that have crossover distortions significant enough to be a problem.
I am not saying well designed class AB amps don't have any crossover distortions but I am not sure if such distortions are at the level higher than that of the AHB2's or high enough to be audible. Feed forward control is nothing new, without knowing how they applied the technology, I am not going to assume it will work as their marketing literature claims. At this point, I believe in Benchmark's marketing information as much as I believe Passlab, ATI, Bryston, Hegel, Parsound's etc., just to name a few. If I am in the market for a 100W/200W power amp today, I won't be going for the AHB2 just because of what I read on the Benchmark website, but their excellent measurements on JA bench certainly help.
