Tommy Hoerning just sent in an email about new Sati/Horning ultimate interstage transformer for indirect driver triode tubes like eml 20 snd demilar.

The sati interstage is unsurpassed by any other high quality interstage transformers.

Induction 380 henry, 50 kohm impedance, 400 ohm wire resistance,  
Frequency response 2 hz – to  2 mega hz plus minus 1 db for 5 kohm load, 10 kohm load 4hz to 1 mega hz plus minus 1 db

Current 50 ma .Weight 7.7 kg and 150 mm in diameter and 100 mm high. The tranformer will produce fine  50 khz square waves. 

But the transformer is not just build for showing ultimate frequency response, it is of course build for achieving the beat sound you can get. For this purpose we have chosen a thing so rare as nanocrystalline torid core because it is the best transformer you can get for this.

Its display of sound is showing how fare you can get with its combination with a super indirect triode like the eml 20 and 30 and other tubes like this.

The high speed of the ultra fine nanocrystalline core shows fantastic hysteres curves and the toroid core shows why it is superior to double c type of cores, every talk about that other cores is batter to play bas is completely undocumented.

And its unsurpassed high frequency response with over 2 mega hz is the background for its great display of tones and over tones in real music triode amplifiers.

The use of the very best core material and the complex work of making the right windings technic, making the right air gab in the nano crystalline core is very complicated and all comes of cause at a given price.