kappen skrev:
HIFI4ALL.DK skrev:
Der er utrolig mange udfordringer i at kontruere kabler. Et af disse problemer er isoleringen, som i mange tilfælde er lavet af plastik (PVC). |
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Hvorfor er det et problem at isoleringen er lavet af plastic?
HIFI4ALL.DK skrev:
| Duelunds løsning på dette problem er brug af forskellige olier og silke som isolering i stedet for pvc. |
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Hvad løser det?
HIFI4ALL.DK skrev:
| Denne umiddelbart anderledes måde at bygge et kabel op på har vist sig igennem års afprøvning af forskellige løsninger vist sig at være den bedste. |
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Hvorfor er det den bedste?
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Den korte version er, at ønsket om at undgå plastic bunder i at undgå statisk ladbare materialer omkring lederen. Jeg har en artikel fra Steen skrevet på godt valbyengelsk, år før vi startede DCA, der beskriver hans indledende forsøg og indgangsvinkel (bemærk han senere foretog visse ændringer i ledergeometri oa.):
Cables
The transmission of signals through cables is disturbed in different
ways.
These disturbances are heavily related to modern time and it’s widely
use of plastics and related topics and further of course to the material
and form of the wire itself.
Cables were at first of no interest of mine, as my primary hobby is
loudspeakers. But two friends Niels and Thorsten had made some
convinced me to look deeper into that area. A new search, which led to
so many interesting results, was started.
In the sea of audio worms offered on the market, one might loose the
orientation and go for the price, assuming there is a connection - the
more expensive the better sound.
I'm really not to judge between them, as they all are wrapped up in
plastics, and I don't like the sound of that material at all.
In my ears it adds a fatness and muddiness to the bass and makes
treble thin, by apparently increasing its lower and upper end, not to be
seen by measurements.
As I hear it, it must have a kind of memory - much like the effect
known from capacitors, and thereby works as
an active element in the
dimension of time
, where it should be silent. This effect explains why
it sounds of more than is measured.
What then? - At first we must make a choice - single core or multicore.
Multi-core has, in my ears, a common sound of their own, which I
don't find with single core.
Single core doesn't sound totally right either, if it is a round wire.
This I used in the beginning - 1 mm round pure silver in different
insulation, where two materials fell out to be good as insulation: cotton
and silk. But there should be others for you to find - flax for instance,
which I haven't been able to find in pure form as thread.
All cable experiments were done with interconnect cables, as they
transport all frequencies and differences are heard with ease.
The form and size of the wire
itself influences the way sound is
transmitted through it.
If you like the sound rounded off in a pleasant manner, you should use
round wire around 0.7 mm in diameter. If you choose them thicker,
you will spoil the precision in the treble.
If you like it very, very precise, you should use thin foil, but then the
lower part of the sound register becomes far to thin without weight.
Here you have to compromise. I have found a balance I like, when the
dimensions of the wire are 0.3 mm thick and 2.5 mm wide. But it is a
matter of taste, and the dimensions can be used in fighting wrong
tendencies other places, in the whole chain of components used.
As earlier mentioned, cotton and pure silk can be used for insulation. It
can be bought as a woven tube.
If you are to classical music, you undoubtedly should choose
silver
with silk insulation
, as the most neutral and with a very precise sound
stage.
Two main discoveries concerning cables.
When the material of the wire is open to air, we have problems: These
are oxidation on the surface of copper and sulphonation on the surface
of silver.
The surface has to be closed from contact with the air. I was working
with pure silver, preferring that material, so electrolytic plating with
gold seemed natural. Surprisingly it sounded better with gold than
without.
This observation led to a new version, silver first plated with copper
and then with gold. That sounded even better, so at this point I paused
- satisfied.
It seems as if the wire should have low resistance in the centre and
higher and higher impedance towards the surface
.
What drove me to my next experiment I can't tell, but I annealed some
of the gold plated cable as well as the copper-gold, and big was my
surprise, when I took the material out of my little kiln. The gold had
disappeared. It couldn't have evaporated, so it had in some way reacted
with the silver/copper - so to say, sunk into it - so the whole purpose
with the gold plating was lost. The gold version turned white and the
copper-gold version turned black. Well! I couldn’t reverse the process,
so there they were for closer listening.
The black version was really awful, but the white-
Surprise! Surprise! It sounded most promising. The whole idea of
protection was cancelled, and a new search began.
A series of plated wires was made with gold in varying thickness.
4,6,8,10,15,20,25 micron. Not at once of course, as it is rather
expensive process, but all were annealed and gradually listened to
always in four versions at a time.
A miracle occurred at 10 micron, 15 even better but at 20 and 25 it was
as if the sound was effected in a slightly wrong manner.
It is easy to see when the thickness is right, the surface should
look
exactly like white paper
used for machine writing. No metallic shine at
all and no cream colour (too much gold)
To explain the physical effect, as I see it, we can regard a cable as a
very long corridor with reflecting surfaces and even adjacent rooms
and the current as waves of sound.
It is then obvious that the dimensions influence on the propagation of
sound, as the reflective coefficient off the walls does and as the
adjacent rooms - (the connectors and insulation) - do as well.
The mixed crystals formed by the silver and gold serves as dampening
the reflections from the walls of the wire, seen from within. The
surface has changed from metallic and mirror like reflection, to nonmetallic
and diffuse reflection - in other words from order to chaos
like, also for the electrons to meet progressively. This slows down the
speed at high frequency, which is forced out towards the surface.
For protection of the surface of the wire, another solution had to be
found.
I had suspected the effect of plastic being caused from its ability to
hold and deliver a static load.
It suddenly came to me, that layer of linoleum on floors doesn't build
that up. This material is heavily based on linseed oil, which is a drying
oil why that was tried for protection of the surface.
At first the wire and later on the wire with is silk insulation was dipped
in the oil and dried at 60 to 70 degree Celsius in an electrical oven. It
takes 2-3 days.
The listening results were
well beyond expectation. I had feared it to
have some deteriorating effect - big was the surprise, as it turned out to
be even better than the gold plated. It was therefore with misgivings
the same procedure was done with the gold plated wire - was all that
much money just thrown away? Luckily their better inside treatment of
the signal worked clearly through.
Used as digital connections I must say the gold plated annealed and
with linseed oil treated cable is without competitions - but the price of
manufacturing - Ugh!
The linseed oil has a secondary very positive effect, as its affinity to
oxygen is very high, whereby the surface of the metal is cleaned
effectively from oxidation and kept in that condition.
Wires have an orientation created by crystallisation of the metal, much
like domains in magnetic material, so it is advisable to mark that, if
they are cut from a longer piece of wire.
When connected they must have opposite direction to one another. In
this way the difference of sound is greatest, when the cable as a whole
is turned - if you can hear the difference hidden.
ß-----------------------
-------------------------------
-------------------------------------------------------
à
Listen for s, t and f sounds and the whole atmosphere in recordings of
choir.
A marvellous recording to judge from is the Philips recording of Misa
Criolla by Ariel Ramirez with José Carreras. Philips 420 955-2
Among other thing listen for the choir, you should clearly understand
the words sung.
Another record I can recommend, is a Opus 111 recording:
“Songs of the world” with Moscow children's choir. OPS 30-157.
Here you are presented children voices and Orf instruments with great
clarity, and a marvellous piano, so naturally recorded.
In general Opus 111 recordings are very good and worth buying, if
you can find recordings of your taste in their catalogue.
Cables for the loudspeaker
These can be made in exactly the same manner.
You may here consider if you want single connection or multi way
connections, and balance the dimensions of the silver for the unit to
connect.
To get the cables to look nice you can, after the treatment with linseed
oil, put on an extra and thicker tube of silk.
Beware of synthetics, when you buy these tubes. They can be pure
synthetic or have synthetics within, without the dealer to know. It is
advisable to check it with fire.
Cotton shall glow, with no melting when the open fire is blown out.
Silk shall be unwilling to burn, but melt, bubble up and smell like
burnt human hair.
I like the end result to behave in a manner, so you can't feel or detect it
to have a metallic wire inside. So I don't hesitate to put it all into the
linseed oil once again, and put on a third tube, to get that behaviour
from the end product. It sounds, as if, the better the wire is protected
from the outer world, the better it sounds. It’s so totally contrary to
plastic insulation.
Håber det besvarer spørgsmålene så nogenlunde..__________________
Med venlig hilsen
Frederik Carøe
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