- Jan 12, 2017
Not necessarily a misconception, but probably out of date. Most of the issues with early class-D amplifiers have been resolved and the treble (and other) early growing pain issues have been (mostly) resolved. There are still cheap amps that have issue IME/IMO, but designs based on standard modules seem to be fine.
The things I worry about in that regard is what John Siau from Benchmark writes here:
"The important difference between the AHB2 and class-D amplifiers is that the AHB2 does not produce switching noise. Class-D amplifiers are measured with brick-wall AES17 filters that ignore the switching noise above 20 kHz or 40 kHz. Tweeters can demodulate this ultrasonic noise and fold it into the audible band.
Class-D amplifier switching noise can create problems in a loudspeaker measurement system. More importantly, this ultrasonic noise may become audible when it is demodulated by the non-linearities that occur in all loudspeakers. This potential source of distortion may detract from our musical enjoyment. Class-D amplifiers are compact and cheap, but are not necessarily a good choice for a high-end Hi-Fi system."
Is this only FUD and marketing fluff, or is there something to it? It's above my technical paygrade. But I do notice that some producers of active monitors still use class AB for the tweeters, and class D for the rest.