"Andre Jute" wrote in message
ups.com

How does negative feedback work?
Negative feedback is simply a negative voltage fed back
from the output to the input amplifying device to offset
part of the harmonic distortion which is present as a
positive voltage.

Wrong. The voltage that is fed back in audio power amps is almost always
positive with respect to the input and output of the piece of equipment.
Therefore it is wrong to call it a negative voltage.

Wrong. The voltage that is fed back in audio power amps is simply a fraction
of the output signal. It is not fed back to offset the distortion, but
rather is fed back to offset the foreward-going signal voltage.

It costs nothing except a loss of gain
and a few side effects such as phase shift and possible
instability which are well known in the mathematical
literature and more or less easily guarded against
depending on the level of NFB.

Wrong. Negative feedback always reduces phase shift. If misapplied it can
cause an amplifier to become less stable, but in fact when properly applied,
negative feedback increases stability.

Negative feedback increases stability in the sense that it stabilizes the
amplifiers most important technical parameters. For example consider the
gain of an amplifier. If there is no negative feedback, then the gain of an
amplifier is very much exposed to natural variations in the parameters of
its active devices whether they be tubes or solid state. For example, the
gain of both tubes and transistors can be very sensitive to temperature.
With negative feedback, the important parameters of the amplifier are set
by a pair of resistors, whose properties can be made to be very stable and
independent of temperature.

You should get the idea by wrong - Jute has no clue about what negative
feedback is, how it works, or what its real benefits are.