In article , Rob
wrote:
Jim Lesurf wrote:
In article , Keith G
wrote:


Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".

But I can't recall anyone making such a statement with no qualifiers.
If you can, perhaps you can post the details of who, when, etc. - i.e.
give the date, time, title, etc, of the posting, and the full wording.


I'm afraid I must shoulder some of the blame. It's my contention that
they don't sound the same - far from it.

A couple of people had the patience to explain that most SS amplifiers
built nowadays simply do sound the same to all intents and purposes
given:

* a reasonable set of operating parameters, principally relating to
speakers; * a certain specification, which most off the shelf integrated
amplifiers meet.

I am not sure what 'blame' you are taking onto yourself. What you write
above is consistent with what I was saying. i.e. That you may have
initially thought someone was claiming that "All amplifiers sound the
same", but it was then pointed out that the statements were qualified along
the lines I have indicated.

Serge (and you) guided me through the whole thing, but I became lost at
a crucial point of measurement (you measure the electrical
specification, I wanted to measure the sound; you said they were the
same thing;

I've not checked, but I am not sure I would have said that they were the
"same thing".

I may have pointed out that the amplifier deals with input and output
voltage (and current) patterns. i.e. electronic signal patterns. Not sound.

From which it follows that if two amplifier give the same electrical output
from the same input, then they should be indistinguishable in terms of what
emerges from the speakers.

(An exception being if one amp nechanically 'buzzes' or 'hums' so giving
an audible unwanted sound.)


IIRC One of the points being discussed was that you can use the electrical
signal levels at the loudspeaker inputs to check that the two amps are
being used to give similar sound volume levels with a given speaker.

You need to do this when trying to compare because if one system plays a
bit louder than the other, then they may sound 'different' for that reason
even when the amps are otherwise identical. Much easer to check the levels
are the same at the loudspeaker input than by trying to measure the sound
pressure level in the room.

Of course, if you keep changing the speaker, or its location, then this
will cause the results to change regardless of choice of amplifier.
Ditto for listening position in the room, etc. This illstrates one of the
various problems that afflict those who try to judge by sound in an
uncontrolled comparison. There are simply too many factors that can
affect that results which have nothing to do with the amplifier.


Slainte,

Jim

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