[Audio_Empire[_2_]]

On Thursday, December 13, 2012 3:45:23 PM UTC-8, Dick Pierce wrote:
Audio_Empire wrote:

For instance. Lets take two modern, solid-state amplifiers. Let us

stipulate that both are fairly equal in power output, distortion and

frequency response.



Those are pretty vague definitions of "measurement". More likely, they

are "specifications," which, as specifications normally are, quite

inadequate measures of performance. In fact, most specifications

like poer output, distortion and frequency response, serve either or

both of two purposes: 1) marketing or 2) minimum required performance

to legally satisfy advertsising vs performance requirements under

some variety of regulatory and consumer protection requirements.



The latter is the most important, in many case. It says, in

effect, that if a manufacturer can show that the amplifier

meets the published specifications of power output, distortion

and frequency response under conditions which (in most cases),

the manufacturer gets to specify, the manufacturer has proven,

legally, that it has met it's legal oblications in the case of a

disoute with an unhappy customer.



As such, these kinds of measurement far far short of even

a moderatly complete set of performance measurements.



But, let's say that one of the amps has an average

run-of-the-mill power supply while the other has a huge supply with

separate and very large power transformers and separate

supplies for each channel capable of sourcing many more amps of

current to the second amp than is available to the first. Now. lets

operate both amps near their limits with difficult loads. I'll guarantee

you that even though they might measure almost identically in the

above mentioned parameters, under normal circumstances, in these

circumstances, the amp with the largest supply is going to sound better.



And, in those circumstances, they would MOST DEFINITELY NOT

measure the same. Among other things, the measured behavior of

the amplifiers would be radically different driving high powers

in to low impedance loads. And that set of measurements is not

in your list above of power, distortion and frequency response.

Nah. I have two amps here one is a Krell i300 with 150
Watts/Channel, but it has only one power supply with a
single toroid transformer. The other is a Harman-Karden
HK-990, which also has 150 Watts/channel. But the H-K
has TWO huge Toroids (both about 30% larger than the
Krell) and totally separate power supplies for each channel.
The H-K just sounds better, especially at high volumes.