Listening to Class D

摘要

If you've ever perceived the slightest gap between the marketing and the metal in an electronic product, you ain't seen noth-in' yet, as the song goes, until you read the promotional materials that accompany audio products. You'd think that the engineering community would have dispensed with the hype long ago. Electronic audio amplifiers, starting with Lee De Forest's triode vacuum tube, are nearly a century old. Even the relatively newfangled Class D is no longer a novelty. From an instrumentation perspective, audio bandwidths aren't challenging, the amplitudes are generous, and the impedances look kindly upon probing.