"William Sommerwerck" wrote in message
...
"Class D amplifiers can be controlled by either analog or digital
circuits.
The digital control introduces additional distortion called quantization
error caused by its conversion of the input signal to a digital value."

I'm sorry, but I consider that to be an ill-informed gobbledy-gook
statement.

It's overly terse, but quite correct (though I would have said "signals"
rather than "circuits").



It is not. We've already agreed that the signal in a class D topology
amplifier, is not converted to any kind of digital value at any point. This
is the fundamental tenet upon which you have based your entire argument that
it is not a digital mode. Since the signal has not been 'quantized' into a
step value, no such distortion that would normally be associated with
quantization error, has been introduced.

I think that you are mis-understanding what the author is trying to convey
in his statement. When he said "controlled by ...... circuits ", that's
probably exactly what he meant, and was referring to control of volume,
balance etc by use of either a fully analogue pot, or a digitally-controlled
pot IC.

However, even if a pot IC is employed, no quantization of the signal takes
place within it, and if for no other reason, he is wrong to suggest
otherwise. A digitally-controlled pot IC is merely a step attenuator, based
on FET-switched resistors. Thus, for all practical purposes, it is no more
than a conventional resistive pot, and introduces no more or less distortion
into the signal path, than a conventional resistive pot would.

Therefore, no matter which way you take his intended meaning, it is still
actually meaning-LESS and ill-informed gobbledy-gook.

Arfa