silver foil transformers

[hifinutt]

Some years back i upgraded my MFA passive classic to a silver wound transformer and it make quite a difference . I am very curious about silver foil transformers , i believe silver wound transformers can be a bit of a pain to wind as they can break [ as mentioned in a thread on the bespoke ]

https://www.whatsbestforum.com/threads/bespoke-audio-tvc-passive-preamp-an-unassuming-star.27032/

Next week i hope to compare an amp from the far east with silver foil transformers

from their blurb :

One of the elements that set ..... equipment apart from the rest is our unique in-house developed and wound silver foil transformers. The mode of operation of these transformers is entirely different from standard wire coil designs, offering extended bandwidth without peaky resonances and significantly improved efficiency. We employ various exotic core materials, including finemet and permalloy and pure silver, alloy, or copper wire depending on application. These transformers are a major reason that .... amplifiers do not sound like typical vacuum tube amplifiers and even our low power single ended models have tremendous dynamics, detail, and drive capability.

are there any advantages sonically to these silver foil transformers ? has anyone used any in their amps or had any experience

[southall-1998_mk2]

Sounds like snakeoil nonsense to me. But if you hear the difference! Each to their own.

S.

[hifinutt]

folks in the far east seem to love the silver wound option on their bespoke , costs many thousands though !!!

[Barry]

Not only do "folks in the east" love silver wiring, they also love to use old silver. Kondo of Audio Note fame would buy up old canteens of silver cutlery to melt down and be drawn into wire. Quite how the age of a conductor matters is lost on me.

[struth]

Maybe the ascociated alloy metals

[Barry]

Maybe, but 'Stirling silver', from which solid silver cutlery is made, is 97.5% silver. Why don't they simply use 'new' Stirling silver to draw down into wire?

[Ali Tait]

Possibly related to the reason some very old valves can sound so good. It's been suggested that the age of the materials may be why.

[struth]

yeah but after being turned into wire its new again, or is it?

[Barry]

I don't know - in the words of Toyah Willcox: "It's a mystery".

[hifinutt]

i am particularely interested in this silver foil and how it can make a difference

this site mentions this

"Electrocube designs and manufactures transformers and inductors using aluminum or copper foil in place of the standard copper wire traditionally used for coil windings. As the result of a company-funded development and testing program, Electrocube introduced this unique construction technology, providing practical and economical aluminum foil-wound transformers in the 25 VA through 50 KVA power range.

For over thirty-five years, these foil transformers have been used in commercial and military applications exhibiting exceptional reliability and efficiency. The use of aluminum or copper foils results in a transformer with many advantages over conventional wire-wound versions:

Increased reliability
Reduced size and weight
Higher ambient temperature operating capability
Improved electrical efficiency
Increased electrical stress resistance
Better overall regulation"

For example, the principal advantage to using aluminum foil rather than copper in transformers is the reduction in weight. The density of copper is .32117 lbs. per cubic inch while that of aluminum is .09765 lbs. per cubic inch. For a given winding volume, the aluminum winding would weigh one-third the weight of the copper. However, aluminum has only 60% the conductivity of copper. If the winding volume is increased by 40% to raise the aluminum conductivity to that of copper, it still leaves the aluminum coil weighing only 42% of the equivalent copper coil.

https://www.electrocube.com/pages/transformers-technical-bulletin-11

[Ali Tait]

AEE will supply Amorphous Core transformers with silver wound secondaries-
https://www.aeetransformers.com/products/audio-transformer.html#options-and-versions