Nick Gorham wrote:

No, of course you can have as many stages as you want so as much gain
as you want, however its gets harder to apply global feedback with
more stages as you start to run into problems with phase shift.

Managing this sitaution is one of those things they teach in engineering
school.

The other side of the above statement, of course, is that the
rationall that goes behind the reintroduction of SE designs tends to
frown on the use of global feedback.

The goal of modern SE design is obvioiusly to design the least accurate
amplifier possible.

It can be heard that increasing
feedback will tend to cause the sound to become closed and in some
way deader.

In the minds of certain delusional persons, yes.

Now some will prefer that effect, but in that case, the
same sound can be obtained by PP amps using feedback, so there is
little point in accepting the other SE problems, including cost and
efficiency if the same percieved sound can be gained elsewhere.

The interesting question is what there is about a high-distortion amplifier
that audiophiles should prize.

However for those that prefer the result of SE with little or no
feedback, then the additional problems are seen as acceptable.

Think of the modern SE amplifier as a good amplifier, front-ended with an
EFX box, such as might be used with an electric guitar.

There is a element of fashion attached to SE design and currently,
part of that fashion is zero negative feed back.

Good choice of words - the modern SE amplifier is a device borne of fashion,
not technology.

As I said, I am not trying to convince anyone of the "correctness" of
SE designs, but just trying to give some answers to the questions
that were raised. Which got onto feedback via the fact that without
global negative feedback its hard to make anything like a linear amp
from non linear devices.

An obviously ignorant statement, given the effectiveness of local feedback.