To be clear, this IS a digital amplifier, and is not a Class D amplifier. Atmasphere will always disagree with me, but given Technics nomenclature and the use of an A/D converter, and PWM output I think if any amplifier qualifies as digital this one does.
What I find kind of interesting here is that the measurements are OK but not absolute Class D killing results. I am particularly unimpressed by the performance of the impedance compensation circuit, LAPC, which at the end of the day does not seem to have performed significantly better than actual, non GaNFET amplifiers, particularly in removing the effects of the output filters Class D amps require. I really hoped to see a huge win here... but it’s not. It’s just making the PWM perform almost as good as a true Class D amplifier.
Lol!! I won't always disagree, unless you say something like this- on the one hand, its a digital amplifier; on the other you discuss class D amps- including Pulse Width Modulation, which is an analog process found in most class D amps.
I'm puzzled by the idea of a 'digital amplifier' since the bits in a digital word represent a voltage, whereas in a switching amplifier the on and off states have no such meaning. At some point the digital signal has to be converted to analog; as best I can make out this might describe a class D amp with a DAC driving it directly.
I've puzzled over their claims about this amp. I think a lot of it is marketing. I've seen claims that the amp is zero feedback and there is also evidence to suggest that there is feedback.
The output impedance of the amp should be very low even if its zero feedback and so should behave as a voltage source even into 2 Ohms. But that means that the output filter will introduce phase shift; to get around it they have a very high switching frequency and thus also a high filter frequency. At least that's my take on it.
Its quite a tour de force of engineering- too bad it didn't bring home the bacon for you.