收到范登豪先生的回复：
The average moving coil resistance of the 4 layer platinum coil is around 500 Ohm DC impedance.
There might be a small variation in this impedance thanks to a minor difference in coil-wire length.
The impedance setting of your input device must therefore minimal be also 500 Ohm.
Where the secondary load is 50 KOhm, your input transformer should have a ratio of 1 : 10.
There are not many of these transformers around, so evaluate your transformer for this specific property.
With a lower input impedance, the sound will lose transparency in the top-end and also dynamics are gone.
And most important: the output level drops down dramatically.
Wish you many happy listening hours,
With Best Audiophile Regards,
A.J. van den Hul.
