charles,
the audio note trannies are only half silver/half copper, Slagle is using full silver over nickel, and I think he must know what he is doing regarding winding.
Not quite sure cobalt/amorphos is what you would want in a step up transformer.
And regarding material...we all tend to extend what we know or think we know to what we really don't know. I am guilty myself.
We all have these preconceived conceptions of what silver sounds like, good silver is smooth as silk and very open with delicate details. Cheap silver is what must of us know.
These silver transformers are super smooth, open, airy with tons of weight and tonal colours, don't be mislead by words.
I would love to bring them to your house one day charles!
We all know people that can build stuff better than the big boys, these may be one of those products.
mike