Good sound found with just test equipment

Good sound found with just test equipment

Arer there really scientists who believe that sound quality involves
non-measurable parameters?

About well-known switchmode power amplifier designer Bruno Putzeys:

* spectrum.ieee.org/feb08/5924

"
He went through four generations of circuit boards without listening to any
of them. Instead, he connected each board to an audio analyzer and then
rejected it because the results weren't what he wanted. The fifth iteration,
though, looked good. Just before Christmas 2001, he brought a pair of the
amps home and connected them to the speakers in his living room. He put on a
CD of Spanish classical music and selected a song by the 18th-century
composer Juan Francés de Iribarren, "Viendo que Jil, Hizo Raya." He settled
back in a chair and listened. It took him just a few seconds to reach a
conclusion: "Straight in the bull's-eye."
"

The point is that Bruno Putzeys clearly believes that technical measurements
were sufficient to establish the sound quality of a high end power
amplifier.

Also:

* w w w .6moons . com /industryfeatures/etf06/etf_2.html

"
The finale was a toss-up because one of the two finalists did not survive
the finish line. The winning design was by Periklis Gurdouparis from Greece.
It had very cheap Chinese D/A-chips and lots of tubes in it. The following
day, Bruno Putzeys of uCD/Philips spoke about making audio measurements
using DACs. He had three of them. One was last evening's winner, the second
a non-oversampling design and the third his own brainchild. The shoot-out
winner measured fairly decently, showing a typical distribution of
distortion components from a tubed output stage. The non-oversampling DAC
was more wanting in this respect but Putzeys didn't condemn such designs
entirely. His own DAC measured essentially perfect - the measurement values
were as good as they can be in practice.
"

Re: Good sound found with just test equipment

Arny Krueger <arnyk@hotpop . com > wrote:
> non-measurable parameters?

> About well-known switchmode power amplifier designer Bruno Putzeys:

> * spectrum.ieee.org/feb08/5924

> "
> He went through four generations of circuit boards without listening to any
> of them. Instead, he connected each board to an audio analyzer and then
> rejected it because the results weren't what he wanted. The fifth iteration,
> though, looked good. Just before Christmas 2001, he brought a pair of the
> amps home and connected them to the speakers in his living room. He put on a
> CD of Spanish classical music and selected a song by the 18th-century
> composer Juan Franc?s de Iribarren, "Viendo que Jil, Hizo Raya." He settled
> back in a chair and listened. It took him just a few seconds to reach a
> conclusion: "Straight in the bull's-eye."
> "

> The point is that Bruno Putzeys clearly believes that technical measurements
> were sufficient to establish the sound quality of a high end power
> amplifier.

The longer version of the article is even more explicit

" At a visitor.s request, he re-creates the event [Putzys' first audition of his UcD module],
with the very same CD and stereo components. The music begins to flow from the speakers, and
Putzeys.s eyes seem to unfocus, like he.s lost in thought. There.s a little grin on his face.
The sound really is remarkable.extremely transparent, neutral, and precise. And yet there.s a
lovely warmth and force in the female vocals, and not the slightest trace of harshness.

. it was a defining moment,. Putzeys says of that experience. "Until then, I had subscribed to
a lot of audio folklore, namely that measurements don.t matter". He had basically moved on
from his adolescent infatuation with vacuum-tube audio. .Tube designers often build and see if
they like it,. he continues. .You never get to question what it is you want to hear. In my
case, what I want to hear is music and nothing else..

In an engineer.s universe, Philips would have swiftly embraced Putzeys.s UcD module,
incorporating it into countless products. In the actual universe, the module basically fell in
the cracks at the giant company. But in April 2003, an enterprising young entrepreneur named
Jan-Peter van Amerongen visited Putzeys at Philips. Some years before, van Amerongen had
started Hypex Electronics to supply amplifiers and other gear to makers of active speakers and
to recording studios. He had heard great things about the UcD.

Ironically, the one thing he didn.t want to hear, at least initially, was music amplified by
the module itself. .The only thing he wanted to see was the output signal on an oscilloscope,.
Putzeys recalls. .He looked at it, and in about one minute he said, .Okay, I want to buy a
license.. He had seen so many dreadful outputs, full of RF hash. He could tell from the signal
whether it was well designed..

Not long after, Putzeys left Philips for Hypex, where he has pretty much free rein to explore
the boundaries of class-D. Just .for fun,. he recently designed an audio amplifier with 0.0003
percent total harmonic distortion, at full power, amplifying a 20-kilohertz signal. That
figure is more than 1000 times better than some very good solid-state amps. In fact, it.s an
improvement that no human ear can detect, as Putzeys acknowledges.

But that figure is also about 30 000 times better than that of some tube amps.a difference
that.s not beyond the ability of human ears to detect. Putzeys rejects the idea, which most
tube-amp enthusiasts take for granted, that it.s okay.desirable, even.for an amplifier to
.color. the music it is reproducing.

.Audio is not supposed to be art,. he insists. .Making music is art. Getting it from the CD to
the listener should not be art.."

--
___
-S
"Hey pip squeak, who's L Ron, some new rapper?" -- Nic