As there is really great interest about the all-new Nagra HD preamplifier here are few more official details:
“The volume control is a patent-pending technology that allows perfect level matching with a much more transparent sound compared to pots and switch resistor technology because there is no attenuation of the input signal, just an automatic selection of a tap on the Nagra custom output transformer.”

The newly developed SuperCapacitor power supply is a new technology which combines the very low noise of a battery with the high current capability of the best linear power supplies.

The audio engineers created a super vibration free stand to lower the microphonic resonances to a new level.
The HDPREAMP has the best specifications ever achieved by any tube preamplifier, 160 dB of signal to noise and 0 Hz to 200kHz frequency response with perfect phase integrity.
The HDPREAMP is able to reproduce a square wave at 16 Hz.

Frequency and phase response. – Green: frequency/Red: Phase 
And the Sound!
The HDPREAMP reproduces music with natural impressions, with full spectrum bandwidth and extreme stability.
It also produces a precise 3D holographic soundstage. It is very difficult to express the impact of this design as we didn’t think it was possible to achieve such an unbelievable result.
Pure emotion…”