Class A, B, C? What do they mean?

Using tuned "tank circuits" on tube gear and harmonic traps on SS gear will help to reduce THD, but that does nothing to get rid of IMD or "in-band splatter" when using a Class C amp. Class D will also suffer from this, but with slightly different results that would vary with design. All of these "problems" occur in audio amps using these design variations also. Sean
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Sean: Have you ever seen an AF Class C amplifier? I have not. RF amps, in particular, pulsed nuclear magnetic resonance instrumentation, I have seen many. Ham operators,many. Nada for audio.

No, i've never seen a Class C amp for audio. My main comments in my last post regarding audio amps pertained to Class D amps. Sean
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I think the new Rowland Amp 301 is a class D or H switching
amp. So how does an audio company who makes class D amps
get around these problems. I assume the faster you oversample the better, but how much I am not sure. I assume
you would have to decimate the data back into the audio
frequency, again I am not sure. Does anybody know????

Most "decent" switching amps run Class A ( or at least AB ) driver stages and then run the output stage in some type of "switched" mode. They do this to maintain as much linearity as they can at the lower level stages that don't pull as much current while increasing efficiency in the output stage where it is quite current thirsty.

As to the "refresh rate", i have no idea. I remember seeing something about 800 KHz with the Sunfire amps, but that may been something about a harmonic of the primary signal. That seems AWFULLY high to me for an audio amp. Then again, such a high rate would offer greater linearity, both in and above the audible range. Sean
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