450 Pound Monobloc Amplifier

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.

I'm interested to see if Stereophile or some other independent publication puts the new Pascal Class D amp from D-Sonic on the measuring bench to see how it compares to recent better Icepower based amps in terms of frequency response/bandwidth.

I don't believe that an amp has to be heavy to sound good. But, I do know to get rated power over the specified bandwidth, you need a serious power supply supply. you can't get around it. Which means that the tranformers must be huge and heavy. Large storage capacitors aren't cheap for the higher rail voltages necessary and they are heavy also. There are "tricks" that some manufacturers use, but they are just that, tricks. However, that is not to say that lower powered amps aren't wonderful. They are. One just needs to be very careful as to what they will be driving and what amount of consistent power is required. I read a review about the Dan D Agistino momentum amps and I would love to hear them. This guy, knows his stuff. I bet they are really great.