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Patrick Turner Patrick Turner is offline
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Lost'n Found wrote:

Do you guys like or dislike feedback in amplifiers?

I know it is a question that . . . . -_- sigh

But still, what do you think?

I think we can't live without feedback, so what is ur feedback?


Say one forgets to mow the lawns.

Wife says, "lawns are looking a bit ragged dear"

Youse start thinkin, "Hmm, no sex tonight if I don't mow the lawns..."

So you go mow the lawns.

The natural order if for man to not mow lawns as often as the audience
around him wishes, and this is his mistake.

The error is pointed out by someone close to him, and action is taken to

correct the mistake and mow the fukkin lawn.

The lawns which are the signal now looks clean and tidy;
the audience is happy.

However such error corrections in electronic NFB are so fast, and happen

with such rapidity that the corrections of errors occur while errors are
made,
and it as if the wife is intimately in contact with the man's brain and
has him
cutting each blade of grass shorter while it grows longer,
so the apearance of the lawn is always beautiful.

The negativity of such feedback may seem indeed to be horridly negative,

nobody likes to be henpecked that much, but in ampifiers that's what
occurs,
only ithe reality is that the mistakes the amp makes are fed back in
opposite phase to oppose their own creation
as they are created so less of a mistake occurs.

Under such circumstances, and considering that no correction system is
perfect
because it includes the forward path of the misbehaving amp
then there are mistakes in this mistake fixing process and it results in

some ""second order"" harmonic products being formed which under some
circumstances
make the amp sound worse than if no NFB was applied.

But where the distortion is less than 10%, the bandwidth without NFB is
adequate,
phase shift low, and applied NFB
about over 14dB, the reduction of THD is going to sound better than had
nothing been done
and no FB applied.

There are many books on the subject of NFB.
Have you read any?

Patrick Turner.