I might have been too casual with jargon here... I used class D as a name for modern IC switching designs in place of the old class A or class AB designs that

I might have been too casual with jargon here... I used class D as a name for modern IC switching designs in place of the old class A or class AB designs that traditionally provided decent fidelity. I guess there are really quite a few classes here now and I don't really know which I have. I bought a rather mid-level Yamaha home theater receiver with Dolby and DTS decoding back in the late 2000s, It is labeled as an HTR-6140 and must be discontinued for many years by now. It has a bunch of DSP scenes/modes. Other than wanting surround decoding and HDMI + TOSlink inputs, I did not geek out on specs. I merely assume it is class D because the whole receiver is pretty light, so no big heat sinks, and it doesn't seem to produce much waste heat compared to older receivers I've used.