Nagra HD PHONO Pre-amplifier Unveiled

All Image Credit: Nagra

After more than four years of R&D Nagra have released the Nagra HD PHONO amplifier that joins the HD PREAMP, HD DAC X and HD AMP monoblocks in the HD family and is set to become the company’s reference phono stage. According to Nagra, the HD PHONO traces its lineage back to the Swiss firm’s first phono stage, derived from the Nagra IV-S reel-to-reel microphone preamplifier stage and its evolution into the phono section of the legendary Nagra PL-P preamplifier.

The HD PHONO is a a two-chassis tube design with the power supply contained in a totally separate CNC-machined aluminum chassis helping to minimize noise. The delicate tube based circuitry is also housed in a CNC-machined aluminum chassis and is a dual-mono, 100% Class A design using 4x EF806S and 2x E88CC tubes, together with a new generation of input transformers. It supports two MC and one MM input on unbalanced RCA connectors with output being available on a single pair of unbalanced RCA connectors.

Nagra’s fourth-generation of hand-wound input transformers provide an initial gain of 26dB and according to Nagra, have a core made from Cobalt that is cryogenically treated in order to improve its performance. An option slot supports the addition of future custom transformers.

Both chassis are suspended in a system incorporating a damped, constrained layer platform, coupled to four isolator-damped towers that provide superior vibration resistance. The second CNC-machined aluminum chassis houses the massive supercapacitor external power supply. This design of supply is said to provide; “all of the advantages of battery-based power supplies, with the added advantage of accepting and delivering charges much faster and with higher current load and cycle stability than battery-based power supplies.” Based on the supply used by the HD PREAMP and HD DAC X, this design is said to incorporate a number of “innovations” providing improved noise and performance.

The design caters for virtually any MC or MM cartridge having a wide range of gain and loading options. They include; a maximum gain of 68.5dB, selectable loading from no load to 390 ohms and 0pF to 220pf, plus multiple equalization curves including; RIAA, TELDEC, NAB 100µS, VICTOR EUR, and VICTOR USA. All of which maybe remotely selected from the comfort of your chair.

Local control is available using the front panel minimalistic knobs, switches, two displays and famous Nagra style modulometer, with remote control available using the handheld remote, RS232 D9 port supporting various home automation options and the DC trigger input (x1) and outputs (x4).