I saw a Nobsound TPA3116 mini power amplifier for $40, so I figured, "Just how bad could that be?" and along with a 24-volt PS for another $10, I was surprised how GOOD the little box sounded, when hooked to my Large Advent Loudspeakers (circa 1975, new foam rings in 1990).
I tested the set-up with a broad range of musical types-- Jazz Classical, Rock, Live Rock, and I was impressed for a $50 Class-D chip amplifier.
Then I plugged the harman/kardon 330i back into the system, and there was no fair comparison.
My conclusion was the Nobsound (which I might add can be bought from another vendor for as little as $25) would be just fine for the garage, or a workshop, with a pair of small speakers. At that price point it was acceptable, listen-able, and surprisingly small. At 90% efficiency, the power draw for the wall-wort would be negligible.
No sense in trying to compare it to some high-end exploitations of the Texas Instrument chip, but in the right circumstance it wasn't THAT Bad.
Unfortunately, folks like to make blanket statements like "Class-D is inferior"... but that is the same as saying "I like Limes but not cherries"...
I see that Professionals have embraced Class-D in PA systems, and some high-end applications are very good. If this technology is like other aspects of progress, in 5-years we will marvel at what amplifiers might look and sound like.
Anyway, as the "Computer Audiophile on the Cheap" -- I gave the Nobsound a fair trial, and deemed it to be just fine, if we are NOT talking about Audiophile listening.
I admit, being unable to best a 1980s era radio receiver is a very tall standard to eclipse, but I didn't want to send it back for a refund, so I will find it a home...maybe hot-wired to my 24-volt power wheelchair, a pair of cheap speakers, and an MP3 player. I can sound as 'Bad' as the folks with external speakers on the cars with huge rims...