On Mon, 05 Jan 2004 09:26:38 +0000 (GMT), Jim Lesurf
wrote:

1) In most cases with decent amplifiers, the THD level stays well below
0.1% from below clipping until the signal vanishes into the noise. This can
be the case for both class-A and AB designs. (So far as I know, no-one uses
class B for audio, and has not done so for many years.)

To support what our wise old sage ;-) has written. I attempted to
measure the distortion of my class AB power amplifier many years ago -
looking for (from memory) fifth harmonic, which is indicative of
crossover distortion, at very low signal levels. The distortion
reading was extremely low and a higher reading was obtained when
connecting the oscillator/attenuator directly to the distortion meter,
probably because of the buffering provided by the amplifier.

From my experience, crossover distortion is only a problem if the
amplifier is poorly designed or faulty.

If you want to see real distortion, try measuring your speakers. Even
better, try them with a tone burst test.


--
Chris Isbell
Southampton
UK