Nagra Introduces Double DSD HD DAC

May 14, 2014

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Since the invention of the first Nagra back in 1951 which revolutionized location sound recording, the Swiss manufacturer hasn’t stopped innovating, allowing continuous progression towards sonic reproduction perfection.

The DAC Digital/Analog converter introduced in its definitive version in Munich represents a new milestone in this direction, typical of the brand, with its alternative solutions, sovereign musicality designed to last.

This converter, baptized the HD DAC, was unveiled in prototype form in “Avant premiere” at last year’s High End show. In the interim period, the company’s engineers have continued optimizing the unit, and it is now in its final version ready for delivery.

The converter uses an innovative technology based on a double DSD format at a sampling frequency of 5.6 MHz, 128 times superior to that of a standard audio CD and twice that of an SACD. This technique allows the resolution to be pushed to extremes. For this digital section, Nagra worked hand-in-hand with Andreas Koch of AKDesign, a pioneer of the DSD format with a great reputation in professional studio environments. The designers concentrated particularly on the signal path and clock precision, so as to provide efficient solutions to the most common problems of digital drift and jitter. An ultra-high performance signal correction algorithm was developed specially.

The analog section was also developed using different routes, without any constraints. A glimpse inside the device reveals circuits with an aspect totally different from those normally employed. Amongst other things, one can see Nagra isolated transformers, used to drive an output circuit designed around a single ended tube. These transformers that provide a voltage gain (No gain is electronically produced), are exceptional pieces, of extremely complex design. Designed and wound in-house, they took several months to perfect. They guarantee a very large bandwidth while maintaining perfect phase correlation. The stability of the analog stage is globally such that no feedback was introduced.

The presence of numerous Nagra branded capacitors also grabs ones attention: They were specially made specifically for this device. Some of them adopt very peculiar technologies, such as bees wax. Some of them were even given cryogenic treatment.

The unit totals 25 independent decoupled power supplies, all highly precise and with very low noise. Most of the critical components were made-to-measure, exclusively for Nagra. Two external power supplies are used to power the analog and digital parts of the unit separately. Upon request, these can be replaced by the Nagra MPS multiple power supply allowing the maximum performance to be achieved.
Flexible and adaptable

The Nagra HD DAC DA convertor was designed to be flexible, even in a professional context. It sports a complete connection panel and is able to accept all formats, PCM 24 bits up to 384 kbits/sec, DXD and DSD x 2. Extensive effort was made to design the audio USB input, particularly where the clocks are concerned, to maintain an extreme precision in terms of data flow management. The unit thus demonstrates comfortable operation in all situations even computer-based environments.

Sumptuous Listening

Throughout its development, the Nagra HD DAC benefitted from a process of validation through listening sessions, with the aim of pinpointing the natural sound characterizing analog master recordings. This method enabled the purest possible sound to be harnessed. Total reproduction of transients and harmonics, exempt from traditional artifacts characterized, until now, by normal digital-to-analog conversion techniques the Nagra HD DAC operates in total respect of the music, maintaining its special presence and depth.

Presented for several trials by the specialized press, the unit received a particularly enthusiastic reception.

Principal Characteristics

• Digital inputs: 2x S/DIF, 2 AES/EBU, 1 Optical, 1 USB Audio (mode 2), 1x I2S (Nagra format).
• Sampling frequency: 5.6 MHz, 72 bits.
• Analog outputs: 1x stereo on RCA, 1x stereo XLR (symmetrical on transformers available as an option).
• Compatible digital formats: PCM 24 bits up to 384 kHz, DXD, DSD x 2.
• Bandwidth: 5 Hz à 40 kHz (+0 – 3dB).
• Signal-to-noise ratio: -128 dBr (linear).
• Distortion: < 0.02% (à -20dBFS).
• Dimensions: 310 x 350 x 76 mm (12.2 x 13.7 x 3 inches).

Source: Press Release