SUT - electrical theory and practical experience

Perhaps this blurb from a manufacturer sums it up more concisely: they say the signal is tranferred "via electromagnetic induction" and creates "power transfer without distortion" 

Audio transformers are typically composed of copper wire windings around a steel or nickel-iron alloy core. Each core material transmits electromagnetic signals differently. Steel has a higher degree of hysteresis (magnetic signal lag), making it better for lower frequency transfer. The higher permeability of nickel makes it ideal for transmitting higher frequencies.

The windings around the core determine the impedance level, which increases, decreases, or maintains the signal level as it passes through the transformer. When the signal enters the transformer via the input (primary winding), it then gets transferred to the secondary winding via electromagnetic induction. More windings around the core correspond with a higher impedance, so if the primary winding has more than the secondary, the signal will decrease (step down). Conversely, if the secondary winding’s impedance is greater than the primary, the signal will increase (step up).

Impedance matching is one of the primary uses of audio transformers. Impedance is determined by the efficiency of the conversion from voltage into magnetic flux. In addition to stepping signals up or down, audio transformers can match the input and output impedance levels to create efficient power transfer without distortion or signal overload. Impedance-matching transformers will not necessarily boost or attenuate the signal but will create balance for an optimal energy transfer.

From:

Understanding Audio Transformers | Triad Magnetics

Dear @karl_desch  Your XP27 is very good design and something that made the differences on what you listened vs the SUT came for the XP27 bass range that not only gives you that depth in soundstage.

I think no SUT can touch the overall bass range management by a good active high gain SS design and one with the niquel core less.

I read this comments from a XP27 owner:

" XP27:
1. Lower noise
2. Lower distortion
3. Deeper bass, more articulate bass, less fat, more impact/punch
4. Better transient attack, fine, more precise leading edge
5. Cleaner, clearer sound, more resolution
6. Deeper stage, better hall information
7.  dynamic, explosive

After dinner, I played the Sheffield Drum Track. Wow. It was explosive and loud with very little distortion. There was incredible nuance between the different types of drums and it had huge impact and dynamics. The different drum characteristics and his technique has never been more discernible.

I am still listening with the Burley Wire IC because it sounds so good, but I plan to send my Transparent Audio cable back for recalibration to see if it will sound even better. The XP-27 has continued to improve over time. It seems that the complete break in period was about ten days. I have now had it in my system for sixteen days, powered on the whole time.

Since Al heard it on the fifth day, the resolution has continued to improve. Low level information is even more clear. Micro and macro dynamics are better. The soundstage is about the same, but the depth has increased. Presence, an attribute of my system about which I am very pleased, is even more pronounced. I have not heard this level of 3-D palpability before. Timbral accuracy has never sounded more real in my system. The overall impression is one of improved clarity and a more natural sound. Everything just sounds more real to me. """"

Btw, could be interesting that your friends can ask to EMIA its measured FR due that even that exist audiophiles that just do not care about that kind of measure is really of critical importance and the manufacturer just " dead silence about " and I wonder why because other SUT manufacturers gives that kind of measure.

R.

Resulting from my discussion had with designer/builders of Amplifiers, there are considerations and preferences in place for the Core Materials to be used and the optimisation of the Windings for specific designs for a Transformer.

I have Power Amp's with Hand Wound Optimised Transformers for both the Power Supplies and Output.

My Valve Input/Output Phonostage is with a Hand Wound Optimised Transformer. 

One of the SUT's in use is a Hand Wound Optimised Transformer.

The SUT's I am keen to experience in my system at a later date are also with optimised Transformers.

Not all Tranx's are equal, I have this info' supplied from valuable resources.

There are those that have a design that will perform a role, and meet a broad spectrum of requirements, these are not optimised to a be used for a Specific role. There are those optimised through design, to perform at their best when used to cover a limited role.     

In Japan, I have even seen the Winding Material taken to the extremes, where it is a material used with a proven progeny, i.e such as removed from a Submarine built from a particular decade prior to the Millenium and used with a specific type of steel as a Core material. Not known, but I would assume, these are used to produce an optimised design for the Tranx to be produced. 

A friend last year, designed and built a Direct Coupled Phonostage, based on the Model I own. Each Transformer in the circuit has a Hand Wound Optimised Design, produced from a certain type of wire for each unique role within the Circuit.  

SUT the f*** up.

@rauliruegas

Btw, could be interesting that your friends can ask to EMIA its measured FR due that even that exist audiophiles that just do not care about that kind of measure is really of critical importance and the manufacturer just " dead silence about " and I wonder why because other SUT manufacturers gives that kind of measure.

it seems you are really good at scouring the web and quoting other people and less adept at researching/understanding what other people write. If you click the link provided in this very thread by @antinn on 11/16 you will see the actual measured frequency and phase response of an EM/IA SUT compared to the venerable Altec 4722.

dave