Ian Bell wrote:

That's not distortion that's clipping.

And clipping isn't distortion? Symmetrical clipping is a sum
of odd harmonics. Asymmetric clipping is a mixture of even
and odd. Clipping also introduces severe IM.

If both gain stages produce only even harmonics, then they
will tend to cancel and the remainder will still be even. If
both produce lots of even and some odd, then the evens will
tend to cancel and the odds sum when combined. The
consequence is that a range of combinations of odd and even
are possible, depending on amplitude and the relative gain
contributed by each of the two stages.

Ian

Ian Iveson wrote:
Ian Bell wrote:

That's not distortion that's clipping.

And clipping isn't distortion? Symmetrical clipping is a sum
of odd harmonics. Asymmetric clipping is a mixture of even
and odd. Clipping also introduces severe IM.


Don't be such a pedantic arse.

If both gain stages produce only even harmonics, then they
will tend to cancel and the remainder will still be even. If
both produce lots of even and some odd, then the evens will
tend to cancel and the odds sum when combined. The
consequence is that a range of combinations of odd and even
are possible, depending on amplitude and the relative gain
contributed by each of the two stages.


Rubbish, the proportion of distortion in each stage is primarily
determined by the signal level in that stage, the last stage thereby
swamping that produced by earlier ones.

Cheers

Ian
Ian

"Ian Iveson" wrote in
message
Ian Bell wrote:

That's not distortion that's clipping.

And clipping isn't distortion?

Of course it is distortion. It is a mixture of even and odd distoriton
depending on how symmetrical it is.

Clip exactly half the waveform, and you get only even order distoriton.

Clip both top and bottom equally, and you get only even order distortion.

But, either are special cases. If you clip exactly half the wave, then the
amount of distortion is the same, regardless of level.

If you clip symmetrically, there is no distortion until clipping commences.

Symmetrical clipping is a sum of odd harmonics.

Agreed.

Asymmetric clipping is a mixture of
even and odd.

Agreed, except for the case of exactly symmetrical clipping, in which case
there is no even order distortion.

Clipping also introduces severe IM.

As does all other forms of nonlinear distortion. IM distortion is often
more prevelent than harmonic generation when music is being distorted.

If both gain stages produce only even harmonics, then they
will tend to cancel and the remainder will still be even.
If both produce lots of even and some odd, then the evens
will tend to cancel and the odds sum when combined. The
consequence is that a range of combinations of odd and
even are possible, depending on amplitude and the
relative gain contributed by each of the two stages.

The problem with clipping is that it degenerates into two special cases -
either equal distortion at all levels, or no distortion until a certain
threshold is crossed.