"Trevor Wilson" wrote in message
...
"Robert Morein" wrote in message
...
"Trevor Wilson" wrote in message
...
"Robert Morein" wrote in message
...
"Annika1980" wrote in message
oups.com...
And don't you ****in forget it!
I have never been interested in cables. I've always figured Radio
Shack
Gold
were good enough for me. However, a friend of mine recently did a
quick
switch of XLO and Tara RSC Decade. One of these brands (which?) is an
open
twisted pair construction, encapsulated in something that looks like
Kapton.
The other is a conventional coaxial construction.
There was an obvious difference. The open-twisted pair wires were
much
brighter than the coax.
I speculate this is due to both low capacitance, and reduced skin
effect.
Unfortunately, these were very expensive cables. Do any reasonable
cables
have similar characteristics?
**I still use some of the cables from these guys:
http://www.apature.com/accusound_chart.asp
when they were imported into Australia. They were very reasonably
priced
and
very good performers. I've performed a large number of blind tests and
am
satisfied that they make a difference, compared to budget cables. In
some
instances, clients do not like that difference. I suggest the silver,
or
silver plated cables will suit your needs. I have no idea what their
cost
is
in the US. My only reservation was the construction quality of the
soldering. This may or may not be an issue in 2005.
--
Trevor Wilson
www.rageaudio.com.au
For theoretical reasons, copper seems a better choice.
The higher the conductivity of the material, the greater the skin
effect.
Hence, silver would cause the greatest reduction in high frequency
response,
rather contrary to what I'm after.
**I don't think skin effect is a problem in your application. I don't know
why, but silver is my preference. Nonetheless, copper Apature cables are
worth a listen.
--
Trevor Wilson
www.rageaudio.com.au
For a given diameter, conductors made of material with low bulk conductivity
have less skin effect than those made of high conductivity material. Thus it
is actually possible that conductive plastic cables would offer improvement.
As far as I am aware, there are only four reasonable possibilities for
signal cable differences:
1. inductance
2. capacitance
3. skin effect
4. dielectric memory
Of these, the first two can be compensated for by tone controls,
equalization, or the like, because they comprise a distributed linear filter
in the cable.
The last two, however, are nonlinear effects, which means that the
degradation they cause the signal, if any, cannot be reversed.
There is an elementary exercise every physics student does in adv.
undergraduate and again in graduate electrodynamics. It's a homework
problem, found in the chapter assignments: to compute epsilon, the depth of
the "skin", at various frequencies, for a particular bulk conductivity. The
answer is, it is very significant in the high treble ( 10 kHz region.)
Paradoxically, the lower the conductivity, the greater the skin depth. The
implication is that what one definitely does NOT want is a conductor with
very high conductivity, because it excludes AC.
The phenomenon of superconductivity is more interesting still. A
superconductor EXCLUDES all time-varying fields. This is a direct result of
the above skin effect calculation: epsilon goes to infinity. If one attempts
to impose a time varying field, with an arbitrary potential, the
superconductor quenches, ie., transitions to a state of normal conductivity.