hence the amp itself gets the moniker "digital" amp and "class D" is
conflated with "digital" when in fact the amplification itself an analog
process controlled by digital microcontrollers.
Our class D amp does not use any digital circuits or microcontrollers. You don't need a computer for a class D circuit.
However, would you agree that what you just excerpted about PWM
describes a process whereby the waveform (square wave being the trigger
for lack of proper terminology at the moment) is a combination of ON or
OFF states in an array of switches (transistors or vacuum tubes) and
that ON = 1, OFF = 0 which would easily lead people to assume that the
process is "digital" even when it was a plain square wave and not a
complex microcontroller dictating the ’sampling’ process?
Yes- I've been aware of the confusion around this topic for some time :)
Finally, would you agree or disagree then, that today's class D amps,
with built in DACs and which use complex microcontrollers to sample the
output and alter the switching algorithms can indeed be called "digital
amps"?
'Built in DAC' suggests that the amp is amplifying an analog signal, since the acronym 'DAC' stands for Digital to Analog Converter'. So as the sentence is written, my answer is no, I don't agree. If we let go of that problem though, another arises, which is that the amplifier portion which has the digital stream as its input still has a lot of analog processes in it to do its job. One example is the dead time circuits that are present in class D output sections. They are essential to prevent shoot through currents which can damage the output devices. Digital circuits don't need anything like that; dead time is an analog issue brought on by the fact that transistors take a finite time to turn on and even longer to turn off. Keep in mind the conversion implications involved because Class D amps usually switch at much higher frequencies than a digital bit stream.
From a marketing perspective, the term 'digital amplifier' (which isn't an engineering term) is lazy writing at best and serves to ironically confuse the market, which readily associates the term with class D (but not in the way that it should; hence the irony). It might apply to any amplifier (Class D or otherwise) that had a DAC built-in.
An amp that I would consider to be a true 'digital amp' would be one where the process of conversion from digital to analog happened only at the output, IOW that the entire circuit is one big DAC.
