DComTalk.com

James Knott wrote:
That gold plating is another issue. If gold is so good (yes, I know it
doesn't tarnish) why are low noise instrumentation connectors made with
silver plating? Does the gold actually improve anything, other than
vendors profit?


You can put down a gold plating about 4 molecules thick. I'm guessing
connectors do it a bit thicker but that uses very little gold. I wonder
if silver can be done that thin.

This could all change. Here's what I was told by someone who should
know. I recently learned that Kodak plans to stop making B&W film. And
that accounts for about 1/2 of the world's use of silver. And silver
prices have been dropping. A LOT. Plus a non trivial amount of the
world's gold comes as a by product of silver mining. Some think the
price of gold will rise. Who knows?

I just looked and silver is under $7. Do the Hunt brothers still own a lot?

I recently learned that Kodak plans to stop making B&W film.

glen herrmannsfeldt wrote:

Robert Redelmeier wrote:

Al Dykes <adykes@panix.com> wrote:

isn't anyone concerned with high-end rolloff for
audio on UTP due to the capacitance ?

LOL! Do you think we have Golden Ears? Odd "capacitance"
that doesn't affect 100 MHz would somehow disturb 10kHz.

If you drive it with a 100 ohm source, then yes, but most line
outputs are 1000 ohms or so. 15pF/ft and 300ft is 4500pf.
4500pF*1000ohms is 4.5us, f=1/(2pi*4.5us)=100kHz, will have
some rolloff at 20kHz.

Telephone wiring uses 600 ohm source impedance and longer
wires. The parallel capacitance is balanced by series inductors
spaced out along the cable.

Actually, telephone cable has appreciable rolloff within the voice
frequencies, which is why loading coils are used when going
significant
distances. The coils flatten the attenuation within the desired
bandwidth,
at the expense of higher frequencies. However I doubt that roll off
would
be significant at the distances used in a home.

As for those "Golden Ears" types, don't you know that their ears are
so
good, that they can hear things that are physically impossible to
hear? A
few years ago, there was a columnist (Larry Klien IIRC) in Radio
Electronics magazine, who'd occasionally take aim at those Golden Ear
types. Seems some of them can listen to two different audio systems,
in
different environments at different times and tell which one sounds
best,
but they also reject A-B tests as invalid. They're also the idiots
who
tend to buy stuff such as Monster cables and other such junk.

"James Knott" <james.knott@rogers.com> wrote in message
news:2LudnVbmRs6nyoneRVn-1A@rogers.com...
glen herrmannsfeldt wrote:

Robert Redelmeier wrote:

Al Dykes <adykes@panix.com> wrote:

isn't anyone concerned with high-end rolloff for
audio on UTP due to the capacitance ?

LOL! Do you think we have Golden Ears? Odd "capacitance"
that doesn't affect 100 MHz would somehow disturb 10kHz.

If you drive it with a 100 ohm source, then yes, but most line
outputs are 1000 ohms or so. 15pF/ft and 300ft is 4500pf.
4500pF*1000ohms is 4.5us, f=1/(2pi*4.5us)=100kHz, will have
some rolloff at 20kHz.

Telephone wiring uses 600 ohm source impedance and longer
wires. The parallel capacitance is balanced by series inductors
spaced out along the cable.

Actually, telephone cable has appreciable rolloff within the voice
frequencies, which is why loading coils are used when going
significant
distances. The coils flatten the attenuation within the desired
bandwidth,
at the expense of higher frequencies. However I doubt that roll off
would
be significant at the distances used in a home.

As for those "Golden Ears" types, don't you know that their ears are
so
good, that they can hear things that are physically impossible to
hear? A
few years ago, there was a columnist (Larry Klien IIRC) in Radio
Electronics magazine, who'd occasionally take aim at those Golden Ear
types. Seems some of them can listen to two different audio systems,
in
different environments at different times and tell which one sounds
best,
but they also reject A-B tests as invalid. They're also the idiots
who
tend to buy stuff such as Monster cables and other such junk.

They're not known as idiots in the indusrty, they're known as
'audiophools' which is a takeoff on audiophile. They're phoolish enough
to pay 10x or more for "OFC" oxygen-free copper wire and other such
bric-a-brac.
http://www.geocities.com/amishfan/audiophool.html
Hey! You, too, can join the many who take advantage of these types.
Just start your own business selling blocks of marble for thousands of
dollars, to put under the turntable so that it sounds better. Like
taking candy from a baby!

James Knott <james.knott@rogers.com> wrote:
As for those "Golden Ears" types, don't you know that their ears are
so good, that they can hear things that are physically impossible
to hear? A few years ago, there was a columnist (Larry Klien IIRC)
in Radio Electronics magazine, who'd occasionally take aim at those
Golden Ear types. Seems some of them can listen to two different
audio systems, in different environments at different times and tell
which one sounds best, but they also reject A-B tests as invalid.

Well, for them hearing has passed from a sensory experience into
a psychological experience. Perhaps a religious experience.
In a free country, we really should respect other religions,
even if we don't much believe them.

They're also the idiots who tend to buy stuff such as
Monster cables and other such junk.

Monster cables are not junk. They're usually fairly decent
midrange cables but sold at outrageous prices with the most
appalling pseudoscience flim-flam.

-- Robert