450 Pound Monobloc Amplifier

"I would really like to see where the other big names like Krell, Pass Labs, Bryston and the others could take the Class D or switching technology in the future."

One thing sure about technology in general, things generally get smaller, cheaper and more efficient over time.

Another sure thing is there will always be early adapters. Those are often not the biggest names but rather smaller upstarts that have something to gain from change/innovation.

Over time, a true innovation will gain more and more traction. Eventually, the more forward thinking big boys catch on. Some never do. You know what happens to them, right? That's why technical innovation and those who can drive it are always in demand.

I think Mapman is correct I have not seen any shootouts of class D vs pure class A either tube or solid state.

Some people argue that class D, as good as it is for the money, cannot really compete with best traditional SS amp. I can see that, especially with still limited bandwidth, but most of the weight is in the power supply that can be definitely class D (SMPS) since it is only holding steady voltage (much easier task than driving complex load with music signal). Rowland does it so why not the others? I think it is for three reasons:

1. Design itself is much more difficult than just
transformer+rectifier+capacitors
2. SMPS have bad rap from crude cheap computer applications
3. Audiophiles still believe that it has to be heavy to
sound good.

Third point is very important - why to design complicated light power supply when market believes that heavy=quality.

In theory, I suspect the difference between best Class D and Class A amps may still be bandwidth, like Kijanki says. Those attune to things happening at the very upper frequency limits of human hearing are probably most likely to notice any difference there. But over time I suspect even that would become a non-issue as technology improves, unless there is some hard law of physics out there that imposes a barrier for the long term.

The bandwidth limit causes phase shift in audible range possibly affecting harmonics summing. My amp, for instance, has -3dB at 65kHz causing 20deg phase shift at 20kHz. Mentioned Rowland model 725 has bandwidth of 350kHz.