[stlrman]

Can someone please explain what the amorphous core is ?
I understand that is makes micro/macro dynamics better. I also have read that it makes the tweeter more sensitive so speakers may be matched with lower watt tube amps.
Thanks,
Todd

[srb]

The magnetic core of the transofrmer is an amorphous metal as opposed to a conventional crystalline metal and makes the transformer much more efficient with less power loss.

According to the RAAL website http://www.raalribbon.com/technology.htm

"Recently, we finished development of Amorphous C-cores application in our ribbons. Some years ago, we were the first to introduce large gap approach in building ribbon transformers and now we are the first to use AMCC's in ribbons for absolutely uncompressed high power transient transfer and, at the same time, even further improving already the best low-level performance in the world today, by decreasing the width of hysteresis compared to HF ferrite cores. For direct coupled tube SE-ribbon, we succesfuly developed 175:1 ratio, -3dB at 120kHz Amorphous C-core transformers that can carry DC idle current of SET. Impedance conversion is about 30000:1, bringing the 0.1 Ohm ribbon up to 3kOhm, good for plate loading of most triodes in HF."

Steve

[Lyndon]

Steve,
But the amorphous core is not some kind of rare element sprinkled by the audio fairy gods, right?
I'm in the process of building a dac, and the main hit to my wallet was the pair of Lindahl transformers at $280 plus shipping.  It does put me in the Missouri state of mind for a "show me" that I can clearly ascertain the audio difference between these transformers and a well built transformer from Edcor or someone else.  I went ahead with the Lindahls, because they are the only ones which will fit the board.
Lyndon

[srb]

I can't really speak to the audio improvements of the amorphous core.  With other steel alloys made with silicon, nickel, cobalt, etc. rising in price, the cost should be more competitive.  But you've experienced the high cost of audio specialty items.  The amorphous core option on the RAAL ribbon is ~ $100.

When amorphous core transformers are sold for power distribution uses, the cost/benefit ratio is easily demonstrated by the reduced power loss that would otherwise be converted to heat.  But with audio, the cost/benefit always comes down to perceived subjective sound quality which is pretty hard to nail down.

Steve

[stlrman]

thanks for your response Steve