I do not know many POWER transformers using Silver windings.
Silver instead of Copper *may* give ~~7% lower resistance (not the same as Efficiency), which is a Very Bad Bargain considering the 150X (your number) price of Silver over Copper.
This lower resistance matters at HIGH loads.
High loads are somewhat "easy". Double the linear dimensions of the transformer. It becomes 8 times heavier (4X-6X the price) but the losses become 1/4 to 1/2 depending if inductance or saturation must be maintained.
In AUDIO our needs are different. If we could magically "gain 7% more power", we would hardly notice the extra 0.3dB more level. If we need "more power" we typically need 2X, 4X, even 10X the power. You won't get this by material choices; iron and copper are not that bad.
What that UI/451 graph is showing is the lower losses at LOW loads. Why would we care? In fact low-load loss is vital for Power Companies. My house has a 25KVA transformer to support a possible peak 240V 100A load, but my typical load is nearer 1KVA. It is likely that an older 25KVA transformer has 0.5KVA core losses even with no load. So on average the power company is churning 1.5KVA of coal but billing me for 1KVA actual use. (Don't cry for them: they build this into the rates.) This is a 24hr/day 30day/bill cost for 20 to 50 years. The long-term cost of this standby loss exceeds the initial cost of the transformer. The company has good incentive to shop for high standby efficiency.
I don't think the use of Silver in *Audio* transformer is entirely rational. Knowing (by the cost) you are "listening to Silver" is sure to make it sound better.
Right - so how does needing more turns (you have to use thinner wire to fit) result in lower copper losses for the amorphous core? Any ideas?
@PRR - excellent points about the utility companies caring about losses but them being insignificant for us consumers.
Read my posts you have me mixed up with the participants of the topic. I do not use silver on the contrary because of its low efficiency in the transformer and the high cost is 150 times more than the copper wire.
In other words, I say that low losses in the magnetic circuit and they are 6 times smaller in an amorphous magnetic core than in silicon steel are good not only for Power Company, but also for audio amplifiers, since they allow reducing the internal resistance of the transformer to alternating current , much cheaper and more efficient than using silver. Many are willing to overpay for silver, getting a small result in reducing resistance and, ultimately, reducing distortion. But few people realized that there is a much cheaper way to reduce distortions in amplifiers that almost nothing will cost you compared to silver, but 1000 times more efficient.
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For those who have not understood anything yet. Here is a comparison of the efficiency of a toroidal transformer over an EI transformer.
https://www.plitron.com/wp-content/uploads/2010/02/Picture5-1.png
Toroidal transformers also use the Power Company, but much less often because of their complexity of winding and high cost.
3-Phase Technology™ offers significant advantages.
But are they only good for the Power Company or are they not used in audio amplifiers because of their high efficiency?
Is high efficiency a fictitious obstacle to using toroids in audio? No, of course, it is because of this that they are appreciated and used in audio!
https://www.plitron.com/wp-content/uploads/2010/02/Picture5-1.png
Toroidal transformers also use the Power Company, but much less often because of their complexity of winding and high cost.
3-Phase Technology™ offers significant advantages.
But are they only good for the Power Company or are they not used in audio amplifiers because of their high efficiency?
Is high efficiency a fictitious obstacle to using toroids in audio? No, of course, it is because of this that they are appreciated and used in audio!
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Please contact this company. These guys know a lot about transformers. Show them a link to this my topic, they immediately understand what you need.
Contact Bridgeport Magnetics Group | 800-836-5920 | Shelton, CT
I feel i am being addressed directly here
Due to my huge enthusiasm for amorphous chokes, some time ago i had my winder produce a power tranny on the same AMCC400 single c-core. With both high voltage and low voltage secondaries, so i could use it in either a tube, or a solid state preamp. After an extended break-in period it remained entirely unlistenable with a grotesque tilt up in tonality and practically no bass. Never thought about testing its efficiency.
When searching this forum you will find some posts about the potential drawbacks of high efficiency toroidal power supply transformers.
For quality in a hifi chain it is important to have "headroom" at places where it matters.
Power supplies are one of those places, and we don't need toroidal power supply transformers to have headroom; it is mere an option.
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I feel i am being addressed directly here
Due to my huge enthusiasm for amorphous chokes, some time ago i had my winder produce a power tranny on the same AMCC400 single c-core. With both high voltage and low voltage secondaries, so i could use it in either a tube, or a solid state preamp. After an extended break-in period it remained entirely unlistenable with a grotesque tilt up in tonality and practically no bass. Never thought about testing its efficiency.
Right; there are much better applications for your precious AMCC400.
Think of push pull output transformers and yes, they make good chokes too.
Unfortunately, c-core can not be more effective by definition than a toroid, even if they are made from the same compositionI feel i am being addressed directly here
Due to my huge enthusiasm for amorphous chokes, some time ago i had my winder produce a power tranny on the same AMCC400 single c-core. With both high voltage and low voltage secondaries, so i could use it in either a tube, or a solid state preamp. After an extended break-in period it remained entirely unlistenable with a grotesque tilt up in tonality and practically no bass. Never thought about testing its efficiency.
This has nothing to do with efficiency but apparently the fact that the AMCC400 power supply transformer got saturated; that could be measured.
An amorphous toroidal power supply transformer would be even more vulnerable because of it's inherent high magnetic efficiency.
Nevertheless, all the best examples of amplifiers have toroids in their composition, probably they just know how to correctly calculate and produce ...
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Douglas Self in his book Audio Power Amplifier design:
"For toroidal power supply transformers, go to a manufacturer with a reputation for making low-field transformers".
"A low-field transformer can be 10 dB better (hum; stray fields) than a standard-quality toroidal transformer. On the downside, the price will be something like twice as much. Low-field transformers are usually slightly larger than a conventional design".
You see, the quality is in "headroom", not in striving for maximum efficiency.
Low-field transformers will have maximum core excitation of some 1 to 1.2 T.
No, he advises low-field transformers, and suggests that low-field toroidal transformers are the best option for minimizing hum and stray fields within a certain dimension.
The same quality however can be reached with c-core and/or EI power supply transformers; in those cases there are other issues to deal with.
The same quality however can be reached with c-core and/or EI power supply transformers; in those cases there are other issues to deal with.
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