(TChelvam) wrote:

Dick Pierce wrote in message
...
TChelvam wrote:
Which "we" are "we" talking about?

Or, how about:

Manson, W., "Digital Sound Signals: Subjective Effect
of Timing Jitter," BBC Research Eng. Div, Great Britain,
Monograph 1974/11, 1974.

Gee, that's fully 11 years before some "we" discovered jitter.


The "we" I was refering to is people like me. Who is looking for great
sound at reasonable price.

Despite all the arguments for and against tweaks and High resolution
format, we are yet to see any one audio engineer who could throw a
challenge to whoever claim that their product improve sound. In the
name of science, has any of audio engineering society hauled up people
who sell Racing Diamond cones or green pen or snake oil? for
misleading the public?

As far as that goes the AES doesn'thave the resources to challenge every
ridiculous claim (the AES is a collegal group of audio engineers not a R&D or
laboratory facility) I've continually challenged those kind of claims and those
type of people.

Perhaps the most well known of people who have done so was David Clark who
(along with David Carlstrom, Arny Krueger and several others) developed the
original ABX protocol and comparitor in the early 80s.

I've challenged manufacturers (refused to perform a promised test when I
visited) and retailers (traveled to Florida at my own expense to proctor a
challenge that said retailer would prove that he could easily "hear" amplifiers
under bias-controlled conditions) and enthusiasts (assembled a fully-tweaked
system and recruited subjects for a bias controlled listening test) yet have
not found anyone (no single subject) who was able to reliably identify
amps/wires and outboard DACs under bias controlled listening conditions.

Or, why can't someone with all the measurements and technical paper in
hand come up with suggestions like the alternative for system of say,
Amati Speakers, Krell Amplifier and Esoterik CD Player at 1/10 of its
price or even 1/5. So the problem with people like us ( my type and
not necessarily you) with a system of 1/10 of aforementioned resort to
tweaks hoping they will get 5/10 of their dream system.

You can do that yourself. Just use your head. But anyway that's done all the
time. Read any issue of Sound & Vision and you'll find such systems being
evaluated.

Help us. Give us a definite answer. Make statement like "Buy $300 Sony
Amplifier instead of $5000 Krell. The measurable difference is so
small that it make no audible difference" or. "Stop wasting your money
Amati , buy Benhinger (I misspelt that) for 1/20 of the price and the
is no audible difference you can tell".

OK under bias controlled conditions a high-end retailer was unable to reliably
identify his multi-kilobuck PASS Aleph monoblock amplifiers vs a used Yamaha
integrated amplifier using in his personal reference system using his
personally selected program material.

A high-end salesman, under modest bias controlled conditions (cloth over
speaker terminals) was unable to reliably identify upscale speaker cables from
zip cord using the very system where he claimed that "pretty amazing"
differences were audible.

A group of audio enthusiasts was unable to distinguish a highly-regarded
outboard DAC from the same signal coming from the analog outputs of the same cd
player and re-routed through the analog inputs of a Marantz CDR-610 (in record
mode) and taken from the headphone jack (the latter was needed to proivide
level matching with the DAC) under blind conditions.

These instances are so common I'm surprised that you haven't seen or heard
about them. But there are so many claims that can be considered snake-oil they
are impossible to keepupwith them all. And the less-responsible
manufacturers/distributors just keep changing the goalposts once the claim is
tested. They either dispute the results or just make up new claims and new
'reasons.'

The last I check, jitter measurements still have a lot of room for
improvement and accuracy. See here ;-

http://patft.uspto.gov/netacgi/nph-P...HITOFF&d=PALL&
p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6,640,193.WKU.&OS=PN/6,640,193
&RS=PN/6,640,193

IMO measurement of jitter hasn't been a problem. But you can check some of this
stuff for yourself. Just find 2 devices you think sound different and then have
another person help you to test whether the differences can still be heard when
you don't know which of the two devices is playing.