I don't believe cables make a difference, any input?

[Curmudgeon]

Originally posted by BudP
...

In transformers, where I do play with stacked dielectrics and actual dielectric circuits in the coil, there is a pronounced "aging" process. When dielectrics are made, they have large areas of dipole charge alignment. They literally arrive ready to stick on the wall for a week.

Some of that charge polarity is discharged during manufacture, but there is a very obvious period of operating time, while the fields being applied randomize these remaining domains. Net effects are found in relative phase change, within the bandwidth, and a gross increase in low level information coherency. All of the small signal cues get aligned with their originating signals, from instruments, voices, etc. and the sound becomes more like a real performance. Please notice I am not saying life like here.

George Cardas has a similar explanation for the changes that take place within the first few hundred hours.

There is a fair amount of faith placed in domain resize and reorientation, within the core material used in amorphous core transformers. Claims of 200 hours of use, to effect this change, are common. I do notice that the coils are wound with Mylar film interlayer insulation and signal dielectric. 200 hours seems a sensible amount of time to randomize the dipole electrons in that stuff, with it's dielectric constant of 3.5 to 4 or so. Most of the polyester resins used for potting also have a constant within that range, so the coil really is a lumped sum parameter capacitor.

I cannot decide which form of aging is actually occurring here. Both would provide more low level information and thereby "soften" transient edges and add internal structure to instrument tones.

There is no test evidence I am aware of for domain changes in core that is in use, for any core materials and very little information on dipole randomization either. So, a good place for someone to look into for a thesis.

I would suspect this same randomization of dipole domains to be involved in electrical circuit aging too, though, I cannot say I have ever been able to pick it out of the changes the out put and interstage transformers go through, in the amps and preamps that use our audio devices.

Brett

Do you play that avatar? Do you build your own amps? If so, ya might want to PM me.

Bud

Are amorphous cores in general audio use these days? Link to core mfrs.?
Have you tried any films beside Mylar? Although I think something like polyprop would be thicker and weaker.

In any event, I thought it a very interesting post. Again.

[BudP]

Well, at the expense of sending you off to spend your money with one of my respected competitors, there are three places I would go, for amorphous core transformers.

First would be Tribute Audio at http://www.tribute-audio.nl/

Makes the best input splitter transformers in the world. Pieter's transformers are highly thought of by other curmudgeons, like Romy the Cat and Lynn Olson.

Next would be here http://www.intactaudio.com/

Intact Audio makes C core SE OPT's of exceptional quality and since they are 100% custom designed and Dave Slagle will keep at it until you are satisfied, this is a good place to go first.

Finally I would send you here http://www.lundahl.se/

Lundahl makes a wide range of devices with amorphous core. They are a bit generic in their attempt to suit many uses with a single transformer and so can suffer by comparison with a purpose designed device, but their quality is first class. They have a first class distributor here in the states at K&K audio and Kevin is a great guy to deal with.

http://www.kandkaudio.com/

As for my use of Mylar? Only as a dielectric containment. A final wrapper around the coil, to match the dielectric constant supplied by the walls and winding base of the glass filled nylon bobbins we wind into.

The actual signal dielectrics are a much higher performance material, that is not permeable with the vacume impregnated polyester resin we use, to quench corona and form the dielectric "lens" that focuses the E Field / D Field interactions, across the signal dielectric barrier, between primary and secondary coil antenna events, within the ferrous boundary, provided by the core.

We do pay very close attention to the permitivity of our completed coil structure and the permitivity of the very low hysteresis storage, core construction of the commercial E/I core we utilize. We use this material because it is out of the picture, sonically, by about 400 Hz.

Meaning that the permeability is so low by this point, that it no longer adds a distinctive distortion to the antenna event, in the coil. Amorphous core stops working at about 18 kHz, so it's signature is available across the audio bandwidth. For reference, 80% nickel stops at 7 kHz and 48% nickel at 3.5 kHz. Core provides distortion if it is operating within it's permeability window.

Our philosophy is to dispense with core activities as soon as possible and use proprietary construction techniques to eliminate about 70% of the materials reminence. Other philosophies use the inherent low reminence of amorphous core but must put up with the core influenced distortions across the frequency bandwidth. Typically amorphous core OPT's use a "slower" dielectric to modify the energy transform from E Field to B Field, at field vector change moments, to keep the amorphous core's initial inductive spike under control.

There are other design philosophies at work at other manufacturers. My opinion is to try as many as you can afford to, and use the ones that suit the other limiting factors in your system and your personal taste in reproduced musical character.

Bud

[Curmudgeon]

Oops, I meant to be asking for links to the amorphous cores/materials themselves; just out of personal curiosity. I spent some time designing magnetics, but they were ferrites for switching supplies or grain oriented silicon steel for line supplies. Amorphous cores were just on the horizon then.

And again thanks for educational posts...

[BudP]

Curmudgeon

Try here, lots of data and nice tools to work with.

http://www.metglas.com/

There are others but these guys started it.

Bud

[sauuuuuce]

I know it's early but I want to be the first one to wish this Thread a happy 8th birthday.

[Luke G]

2003 + 8 = 2011

[AJinFLA]

Originally posted by planet10
A human's hearing can be dramatically improved with training & experience.

Yes, absolutely. Just like training and experience is required to run longer and faster. It takes quite a bit of training to run 100m in less than 10 seconds, though perhaps there might be an extremely rare individual who can do so naturally, with little or no training.

Originally posted by planet10
Statistically, given the number of participants, there should be some here that can't hear what others find quite obvious.

You betcha, statistically, some participants here will be able to run faster than others, run 100m times that others will simply be unable to do no matter what. How do we know? Well, it's quite easy. You electronically time them running on a precisely measured 100m lane, with controls in place, like wind speed and certain track parameters, etc.
Now suppose there are participants, lets call them "audiophiles", who brag, boast and boldly claim repeatedly that they can run 100m in less than 10 seconds, but only on their special, self constructed tracks, in their backyard, by themselves or in front of select relatives/friends, using their own method of "timing".
That they have "trained themselves through experience" to run this fast and can tell exactly how fast they were running to within 0.1 db, excuse me...seconds, without even looking at a timer, etc, etc. (but that this took months/years to get exactly right)
When asked to demonstrate this rare ability on an olympic track, electronically timed in front of officials, they absolutely refuse to do so and come up with every excuse under the sun as to why olympic tracks are flawed, why electronic timing is useless, why unfamiliar witnesses causes stress that slows them into running 14+ seconds, etc, etc, etc, etc....
Then sane people laugh at their claims of greatness and refusal to demonstrate, angering and frustrating the claimers. But, of course, in no way slowing the claims, safely sitting behind a computer keyboard.
Sound familiar?

cheers,

AJ

[tinitus]

Wow, thats really intelligent, I am impressed...just wonder where this pronounced contempt comes from

[auplater]

If you don't see it, here's a clue;... it's due to the presentation of presumed superiority and authoritative comprehension of psuedoscientific technobabble w/o a shred of supportive evidence in validation of misrepresentations in a tone of patronizing self aggrandizement...

(back to lurking)

John L.

[tinitus]

Wonder who...well, I am not even allowed to say the "F"word