The Hifi Trajectory Of Class D Amplifiers

Mapman, there are some highly praised class D bass heads (like Ampeg micro or Gens-Benz Shuttle series) and some really bad ones, like with anything else.

To me liquid midrange of class D, that you mentioned, is closer to tube amp than SS amp sound. Other than that my class D amp is pretty neutral sounding. You like a little bit of warmth, that tube preamp gives you and I get the same from my warm sounding speakers. Either way, Icepower is a very good amp, for the money.

Class D progress, in my opinion, is related more to switching speed of output Mosfets that would allow to lessen phase shift by extending audio bandwidth. Companies like Fairchild or International Rectifiers announce new faster, higher power Mosfets every year. That is bottleneck IMHO. Everything else is only matter of integration level. It is also worth mentioning that modern class D modulator is not a simple ramp and comparator but resembles more Delta Sigma A/D converter. In fact PWM is a byproduct of Delta Sigma conversion, that appears alone as SACD. SACD is pretty much class D output (PWM) at high carrier frequency (2.8MHz) before filtering.

Kijanki, agree.

Neutral liquid midrange is a good thing.

I have insufficient data points to say all class d sounds that way but ice power does seem to.

I disagree with the premise that class d has not yet arrived.

I also disagree. Class D amps have arrived. I was a skeptic until I borrowed a pair and used them in my system for a week. I am very happy with my system's overall presentation now. Fantastic low end, dynamics, and smooth articulate midrange. Not to forget a silky smooth and extended high end with such a low noise floor, it makes the music sound that much better. The issue is more being able to admit that fact and hanging onto past prejudices to satiate the ego. The digital camera comparison is a great analogy.

I have two integrateds, one a Peachtree Grand X-1 (class D) and an Audio Research VSi55 running KT120 tubes. Through first Proac D2, then Wilson Benesch Arcs, now BMC PureVOX speakers, I can't tell the two apart other than that the Peachtree is more powerful and will play louder. At volume-matched levels, I cannot distinguish between the two. The only time they sound different is if I engage the tube buffer (running two upgraded Cifte 12AU7) on the Peachtree, then it's actually a little warmer than the Audio Research. But with the tube buffer off, it's apples vs apples. It's my opinion that the ARC VSi55 puts out more than acceptable sound quality, ergo Class D has officially arrived, at least in my house.