All About Class D amplification

WOW , such wonderful information - thank you. ( ? why had I never Googled ? )
I knew that MOSFETs with their high frequency capacity had played a part (plus their negative temperature coefficient helping)
but I just hadn't realized the 'GENIUS SIMPLICITY' involved. (hard ON hard OFF = near zero heat)
The whole PCM + evolutions thing reminds me of that quote:
"Any sufficiently advanced technology is indistinguishable from magic"
I have two questions:
What is a typical 'clock-frequency' of a modern (pcm) class D amplifier?
Are there any pictures of the Sony TA-N88?
 
That looks more like Class G to my eyes. The original magnetic amplifier is just something else.
You are on the right track. It was a Class G amp with some special power-supply.
It had a transformer which was underdimensioned from the core size point of view with a phase-controlled modulator on the primary side. It was able to deliver high peak power.
Despite its name it didn't have anything in common with a magnetic amplifier.

The oldest schematic diagramm of a class-d amp that I have seen was from WW2. It used tubes and was part of an AC power converter.

Regards

Charles
 
At this point in time, are there any (non PA.) class-D amps that are considered to be the HiFi 'state of the art'?
I would sugeest that you do not begin by looking down upon PA amplifiers, as most have more than enough fidelity to be used in a home setup. On the other hand, many HiFi products don't even have proper documentation.

Of course, the HiFis are shiny, while many PA amps are painted with dull colours (and often matt finished) so that they don't cause distractions or draw unnecessary attention (glare, reflections etc. ) when used alongside the powerful lighting setups in large venues.