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Audio Theory, Setup, and Chat > Premium AC cables are such a scam
arnyk's Avatar arnyk 07:49 AM 02-29-2012
Quote:
Originally Posted by Chu Gai View Post

Out of curiousity, if I had two outlets, identical in all respects other than was was cryo'd, and I mixed them up, how could I tell them apart?

You probably could not. Cryogenic treatment IME does not significantly change the exterior appearance of treated objects.

Presumably, if you cut sections out of the parts, polished and treated them to bring out any changes in the microscopic structure and looked at them with a microscope, you might be able to see some differences. That's a standard way to make the effects of thermal treatment of metal objects visible, and IME it works. Metalurgy 110.

Interestingly enough, I see people cautioning against cryogenic treatment of plastic parts.

The parts of electrical plugs and outlets that are being treated would then *not* include the plastic parts. IOW, the brass parts would be treated.

This seems to be a relevant paper about cryogenic treatment of brass:

http://www.tuftl.tufts.edu/musicengi..._paper_asa.pdf

"Abstract. The acoustic eect of cryogenically treating trumpets is inves-
tigated. Ten Vincent Bach Stradivarious B[ trumpets are studied, half of
which have been cryogenically treated. The trumpets were played by 6 play-
ers of varying prociency, with sound samples being recorded direct to disc
at a sampling rate of 44:1 kHz: Both the steady-state and initial transient
portions of the audio samples are analyzed. In some cases, a slight shift of
power in the harmonic spectrum toward the higher frequencies is observed in
the treated trumpets. However, no statistically independent results are seen,
and the most pronounced results were not repeatable. Dierences observed
in player-to-player and trumpet-to-trumpet comparisons overshadow any dif-
ferences that may have been brought on due to the cryogenic treatment. All
data was collected in a double blind fashion. The treatment itself is a three
step process, involving an 8 hour linear cool down period, a 10 hour period of
sustained exposure to -195C (-300F), and a 20-25 hour period of warming
back to room temperature."

The key text would appear to be:

However, no statistically independent results are seen,
and the most pronounced results were not repeatable.


IME measurable changes to resonance are part and parcel of any significant change to the structure of a metal. For example, hardening metal tools makes them resonate audibly differently when you tap on them.

It seems reasonable to say that cryogenic treatment of brass articles may make minimal changes to their metallic structure or no changes at all.

Other sources claim that cryogenic treatment of brass has the effect of relieving stress. This means that their dimensions and shapes are more stable. They are less likely to warp. However, they are talking about changes on the order of thousands of an inch or less. The size and shape of metal parts in an outlet or plug are not that critical. They are designed to flex in use and be self-aligning.
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DonH50's Avatar DonH50 08:16 AM 02-29-2012
Cryo'd trumpets are debated as much on the trumpet forum I help moderate as cables are here.

Look, cryo is tough, but you could just heat-anneal your outlets instead. Rather than having to deal with a source of liquid nitrogen (or helium, if 77K is not good enough and you want to go lower), why not just pick up a blowtorch kit from Home Depot, Wal-Mart, Lowe's, or where ever and proceed to blast each of your outlets? Might as well do the connectors on your equipment and all your cables while you are at it... After heating them to red-hot, the metal should cool perfectly aligned and stress-free, and no doubt the process excites the electrons so they now flow faster and more uniformly than if you froze the poor little buggers. This should provide much more extended high end and quicker bass, provide a more enveloping sound field, improve the imaging and noise floor, and greatly enhance the harmony of the universe.

Good grief...
FOH's Avatar FOH 09:06 AM 02-29-2012
All in chronological order

Regarding powerline capacitors;

Quote:
Originally Posted by FOH View Post

Capacitor banks on power line have a complex interaction with the delivered product. However, primarily, the added capacitance is for power factor correction

later;

Quote:
Originally Posted by arnyk View Post

The capacitor banks are not there to clean noise off the lines. They are there to correct power factor

-----------

Regarding elements that affect the imaging/soundstage;

Quote:
Originally Posted by FOH View Post


Typically, it has nothing to do with anything between the transducers

The choices made prior to, and including the source mics, all the way until the playback loudspeakers, and the choices made there-after. The stuff in between,...isn't typically the issue with modest, yet competent gear.

later;

Quote:
Originally Posted by arnyk View Post

Soundstage is generally controlled by the source recording, the loudspeakers, and the listening room.

I'm honored.

Thanks for that Arny
jneutron's Avatar jneutron 07:39 AM 03-01-2012
Quote:
Originally Posted by Speedskater View Post

I think that Jneutron (who is a cryo expert) wrote that it was a bad idea for the non-metal parts.

It is said that experience is the best teacher...I have been taught well. (via failures of parts).

When a plastic is subjected to cryo, several things can happen, few of them good.
1. Internal stresses of a machined or molded plastic part can be "relieved" during cryo by internal differential contraction, base contraction around metals, or simple failure at a stress concentration. The vendors do not have the ability to see this at the microscopic level, the casual user certainly cannot. Any plastic part which by design, is supposed to dielectrically isolate two parts, like hot to ground, hot to neutral, and has been structurally compromised by cryogenic temperatures, is a bad thing.

Any feature in a piece of plastic which has been molded in or machined in, incurs the possibility that there are stresses within that will not enjoy cryo.

2. Plastics shrink in the 100+ PPM/degree C range, whereas copper is 16, steel is 12, aluminum is 25. Any metal part inside a slot or opening of a plastic part designed to constrain it physically, will shrink far less than the plastic surrounding it. The metal will not give in this case, but the plastic will. At the temperatures where the forces will be the highest, the plastics are brittle and non flexible.

3. Wire insulation becomes brittle cold. The purpose of the bending radii limitation in the NEC is to prevent insulation degradation over time...if you have an overly tight bend in a wire, the insulation on the outside of the bend is in high tension, the inner is in high compression and typically buckles. Any insulated wire which is exposed to cryo has to, by design, have a defined bending radii considerably larger than code for room temp, as the stressed insulation will crack.

The most dangerous aspect of cryoing parts which have NOT been designed to maintain integrity through the process is that of the failures which are not spotted.

I maintain that there are very very few (if any) audio vendors out there who have the expertise to know what to look for and where to look for it... to guarantee that what was done to the part did not compromise it's safety.

Polyimide (kapton) is the best plastic for cryo survival as it retains flexibility even in liquid helium. However, it is NOT self extinguishing should an arc develop. It was for that reason that it is banned in all military flight hardware (and should never be used in the home for any wiring). Tefzel is not as good, but is more abrasion resistant and retains some flexibility past liquid nitrogen temperatures.

But honestly, cryogenic treatment does not alter the room temperature current carrying properties of a normal metal, but can alter the physical properties a tad.

Cheers, jn
Chu Gai's Avatar Chu Gai 08:48 AM 03-01-2012
This assumes, John, that the cryo'd parts really are cryo'd.
roadster-s's Avatar roadster-s 10:27 AM 03-01-2012
Quote:
Originally Posted by Chu Gai View Post

This assumes, John, that the cryo'd parts really are cryo'd.

Ouch!
jneutron's Avatar jneutron 10:42 AM 03-01-2012
Quote:
Originally Posted by Chu Gai View Post

This assumes, John, that the cryo'd parts really are cryo'd.

No, it does not.

You are considering only whether or not the procedure was performed. That in no way involves what I've stated, but is instead, an issue of fraud.

Sentence two of mine:
Quote:


""When a plastic is subjected to cryo""

Cheers, jn
DonH50's Avatar DonH50 12:57 PM 03-01-2012
As long as we are off-topic... What is the definition of cryogenic, temperature-wise? I assume 0 degC is not, and 77K is, but is there an accepted temperature at and below which it is considered cryogenic?
amirm's Avatar amirm 01:14 PM 03-01-2012
Quote:
Originally Posted by DonH50 View Post

As long as we are off-topic... What is the definition of cryogenic, temperature-wise? I assume 0 degC is not, and 77K is, but is there an accepted temperature at and below which it is considered cryogenic?

I am only familiar with their use for sharp tools and there, the temps way low at around -200 to -300 F. Here is an example treatment at -300: http://www.nitrofreeze.com/knives.html
Swampfox's Avatar Swampfox 01:35 PM 03-01-2012
Quote:
Originally Posted by amirm View Post

I am only familiar with their use for sharp tools and there, the temps way low at around -200 to -300 F. Here is an example treatment at -300: http://www.nitrofreeze.com/knives.html

What tools do you cryo?
jneutron's Avatar jneutron 02:26 PM 03-01-2012
Quote:
Originally Posted by DonH50 View Post

As long as we are off-topic... What is the definition of cryogenic, temperature-wise? I assume 0 degC is not, and 77K is, but is there an accepted temperature at and below which it is considered cryogenic?

No idea. The warmest I've dealt with is 77K, and that's only because liquid nitrogen is so cheap, even more than solid CO2.

Maybe the metallurgists consider anything below the martensitic finish temperature to be cryo...not sure.

Cheers, jn
amirm's Avatar amirm 02:26 PM 03-01-2012
Quote:
Originally Posted by Swampfox View Post

What tools do you cryo?

Personally none . But woodworking saw blades came out a few years back that were cryo treated as to make them last longer. I read a review of one 4 or 5 years ago. Never bought any though as with so little time I have for woodworking, my standard blades stay pretty sharp!
Chu Gai's Avatar Chu Gai 02:37 PM 03-01-2012
Quote:
Originally Posted by jneutron View Post

No, it does not.

You are considering only whether or not the procedure was performed. That in no way involves what I've stated, but is instead, an issue of fraud.

Sentence two of mine:


Cheers, jn

You know what I meant John! Fraud? In this hobby? Perish the thought.
DonH50's Avatar DonH50 06:34 PM 03-01-2012
There's no fraud, only marketing...
AJinFLA's Avatar AJinFLA 06:38 PM 03-01-2012
I had some cryoed ice cream today. Way better than room temp.
roadster-s's Avatar roadster-s 06:44 PM 03-01-2012
Quote:
Originally Posted by DonH50 View Post

There's no fraud, only marketing...

For the gullible marketing, but hey, it's their money...
kenglish's Avatar kenglish 09:27 AM 03-04-2012
Quote:
Originally Posted by arnyk View Post

Agreed. Making your own power cords is like making your own rain water.

BTW last time I looked, a shielded IEC cable ran under $10 from the usual web electronics parts houses - Mouser, Digikey, etc.

The unshielded ones are just about give-aways.

I was talking about people who need, or want, a better cable. The original ones are usually fine, but if you have some issues with RF interference, or you just need to make up a special length or whatever, you can make them for a reasonable price.
And, a good plug and receptacle are a good idea at the wall outlet.
But, not for a ton of money.
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