@geoffkait
Yeah, you basically did say they can behave like diodes. That's the entire Crux of your argument. A cable embodies 3 passive characteristics; capacitance, inductance, and impedance. Those properties remain consistent regardless of the direction of energy flow. So saying a length of wire can magically become directional is the exact same thing as saying it behaves in some way like a diode. The formulas that describe the behavior of a diode are how you'd have to describe a directional wire. But since those properties have never been actually demonstrated through any measurement, we can rightly conclude that a length of wire transmitting audio bandwidth AC is not directional in the slightest. The same goes for fuses. |
Cable Break-in
There are many factors that make cable break-in necessary and many
reasons why the results vary. If you measure a new cable with a
voltmeter you will see a standing voltage because good dielectrics make
poor conductors. They hold a charge much like a rubbed cat’s fur on a
dry day. It takes a while for this charge to equalize in the cable.
Better cables often take longer to break-in. The best "air dielectric"
techniques, such as PFA tube construction, have large non-conductive
surfaces to hold charge, much like the cat on a dry day.
Cables that do not have time to settle, such as musical instrument and
microphone cables, often use conductive dielectrics like rubber or
carbonized cotton to get around the problem. This dramatically reduces
microphonics and settling time, but the other dielectric characteristics
of these insulators are poor and they do not qualify sonically for
high-end cables. Developing non-destructive techniques for reducing and
equalizing the charge in excellent dielectric is a challenge in high end
cables.
The high input impedance necessary in audio equipment makes uneven
dielectric charge a factor. One reason settling time takes so long is we
are linking the charge with mechanical stress/strain relationships. The
physical make up of a cable is changed slightly by the charge and visa
versa. It is like electrically charging the cat. The physical make up of
the cat is changed by the charge. It is "frizzed" and the charge makes
it's hair stand on end. "PFA Cats", cables and their dielectric, take longer to loose this charge and reach physical homeostasis.
The better the dielectric's insulation, the longer it takes to settle. A
charge can come from simply moving the cable (Piezoelectric effect and
simple friction), high voltage testing during manufacture, etc. Cable
that has a standing charge is measurably more microphonic and an uneven
distribution of the charge causes something akin to structural return
loss in a rising impedance system. When I took steps to eliminate these
problems, break-in time was reduced and the cable sounded generally
better. I know Bill Low at Audioquest has also taken steps to minimize this problem.
Mechanical stress is the root of a lot of the break-in phenomenon and it
is not just a factor with cables. As a rule, companies set up audition
rooms at high end audio shows a couple of days ahead of time to let them
break in. The first day the sound is usually bad and it is very
stressful. The last day sounds great. Mechanical stress in speaker
cables, speaker cabinets,
even the walls of the room, must be relaxed in order for the system to
sound its best. This is the same phenomenon we experience in musical
instruments. They sound much better after they have been played. Many
musicians leave their instruments in front of a stereo that is playing
to get them to warm up. This is very effective with a new guitar. Pianos
are a stress and strain nightmare. Any change, even in temperature or
humidity, will degrade their sound. A precisely tuned stereo system is
similar.
You never really get all the way there, you sort of keep halving the
distance to zero. Some charge is always retained. It is generally in the
MV range in a well settled cable. Triboelectric noise in a cable is a
function of stress and retained charge, which a good cable will release
with both time and use. How much time and use is dependent on the design
of the cable, materials used, treatment of the conductors during
manufacture, etc.
There are many small tricks and ways of dealing with the problem. Years
ago, I began using PFA tube "air dielectric" construction and the charge
on the surface of the tubes became a real issue. I developed a fluid that adds a very slight conductivity to the surface
of the dielectric. Treated cables actually have a better measured
dissipation factor and the sound of the cables improved substantially.
It had been observed in mid eighties that many cables could be improved
by wiping them with a anti-static cloth. Getting something to stick to
PFA was the real challenge. We now use an anti-static fluid in all our
cables and anti-static additives in the final jacketing material. This
attention to charge has reduced break-in time and in general made the
cable sound substantially better. This is due to the reduction of
overall charge in the cable and the equalization of the distributed
charge on the surface of conductor jacket.
It seems there are many infinitesimal factors that add up. Overtime you
find one leads down a path to another. In short, if a dielectric surface
in a cable has a high or uneven charge which dissipates with time or
use, triboelectric and other noise in the cable will also reduce with
time and use. This is the essence of break-in
A note
of caution. Moving a cable will, to some degree, traumatize it. The
amount of disturbance is relative to the materials used, the cable's
design and the amount of disturbance. Keeping a very low level signal in
the cable at all times helps. At a show, where time is short, you never
turn the system off. I also believe the use of degaussing sweeps, such
as on the Cardas Frequency Sweep and Burn-In Record (side 1, cut 2a)
helps.
A small amount of energy is retained in the stored mechanical stress of
the cable. As the cable relaxes, a certain amount of the charge is
released, like in an electroscope. This is the electromechanical
connection.
Many factors relating to a cable's break-in are found in the sonic
character or signature of a cable. If we look closely at dielectrics we
find a similar situation. The dielectric actually changes slightly as it
charges and its dissipation factor is linked to its hardness. In part
these changes are evidenced in the standing charge of the cable. A new
cable, out of the bag, will have a standing charge when uncoiled. It can
have as much as several hundred millivolts. If the cable is left at
rest it will soon drop to under one hundred, but it will takes days of
use in the system to fall to the teens and it never quite reaches zero.
These standing charges appear particularly significant in low level
interconnects to preamps with high impedance inputs.
The interaction of mechanical and electrical stress/strain variables in a
cable are integral with the break-in, as well as the resonance of the
cable. Many of the variables are lumped into a general category called
triboelectric noise. Noise is generated in a cable as a function of the
variations between the components of the cable. If a cable is flexed,
moved, charged, or changed in any way, it will be a while before it is
relaxed again. The symmetry of the cable's construction is a big factor
here. Very careful design and execution by the manufacturer helps a lot.
Very straight forward designs can be greatly improved with the careful
choice of materials and symmetrical construction. Audioquest has built a large and successful high-end cable company around these principals.
The basic rules for the interaction of mechanical and electrical
stress/strain variables holds true, regardless of scale or medium.
Cables, cats, pianos and rooms all need to relax in order to be at their
best. Constant attention to physical and environmental conditions,
frequent use and the degaussing of a system help it achieve and maintain
a relaxed state.
Insights - Cable Break-in
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kosst_amojan
@geoffkait
Yeah, you basically did say they can behave like diodes. That’s the entire Crux of your argument. A cable embodies 3 passive characteristics; capacitance, inductance, and impedance. Those properties remain consistent regardless of the direction of energy flow. So saying a length of wire can magically become directional is the exact same thing as saying it behaves in some way like a diode. The formulas that describe the behavior of a diode are how you’d have to describe a directional wire. But since those properties have never been actually demonstrated through any measurement, we can rightly conclude that a length of wire transmitting audio bandwidth AC is not directional in the slightest. The same goes for fuses.
>>>>>>I never said wires or cables act like diodes. Don’t put words in my mouth. You’re the only one saying that. Unfortunately for your argument, resistance of wires and cables measure differently depending on direction. Which is one way to determine proper direction. Another way is to listen. If you had done your homework prior to getting involved here you would have known that. God gave you two ears and one mouth for a reason.
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jea48, that’s fascinating, all that stuff on break-in you just posted, but what does that have to do with the price of spinach? Well, OK, maybe there is one thing. You say Audioquest has built a large and successful high end cable company by making cables symmetrical. Yet, gentle readers, we know from this very thread Audioquest is one of the biggest proponents of wire and cable directionality based - according to them - on the physical asymmetry of the wire. Which is why Audioquest has been marking their cables including - and more to the point! - their SPEAKER CABLES for direction since like forever. Therein lies a great big old contradiction. Raise your hand if you need help. Talk among yourselves. Smoke if ya got em. |
anyone here a scientist? Raise your hand if you are a scientist.
BTW, an engineer is explicitly NOT a scientist.
The two receive fundamentally different educations, right from the get go and throughout their training.
A scientist is trained in theory.
The engineer is trained in LAWS.
Both bits are the same, except a scientist is wired to question the theory, where the engineer is taught that these concepts are scientific law and inviolate.
The scientist is the only one of the two that is correctly trained.
The engineer is literally ~purposely~ mistrained so they won’t try to engineer a solution that is based on guesses. They are specifically taught not to think that way. Trained to ’engineer solutions’, NOT to deal with unknowns....Specifically to not deal with unknowns. I hope that is clear. You should never build a giant bridge, skyscraper, or rocket.. based on guesses and theory. Please and thank you. However, this mentality can and does bite scientific exploration on the ass. Repeatedly. The engineer tends to not understand that they are mistrained, as it rarely creates issue in their lives and they (some of them) can generally bully their way past the seeming roadblocks.
This is why some choose the endeavor of engineering over that of science theory and exploration. A mental mindset orientation thing. Just like all areas of chosen endeavor.
If you think I’m tying to be mean or confuse the issue, please go and ask the head of your local physics department at your local university. Please. You’ll get the same answer all the way up through Harvard, MIT, Max Plank institute, all of them will tell you that there are no laws and there is only theory...and that everything, everything under the sun... is subject to change and modification, if observation and then attempts at correlation/proofing... provide the path. But, importantly, that an inability to prove via extant methodologies... does NOT provide for falsification of the observation, just that no path to yay or nay --yet exists. THAT is science.
Only engineers and technicians get taught the scientific law bit. Nobody else.
So when we get this issue of "not being possible", or "not being real"or "it has to be a bunch of bunk and no one here uses science", you can bet your bottom dollar it is coming from an engineer or a technician, or someone who has no real scientific training at all.
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