Nagra Reference DAC

For all of its nearly three quarter of a century existence, Nagra has been, first and foremost, research and development driven.

When introduced, Nagra's HD line set new technical and sonic standards that reflected years of thoughtful research combined with exhaustive listening tests. Since our founding in 1951, Nagra's company culture has driven its pursuit of perfection. Combine this with the Swiss tradition of precision engineering and it was inevitable that continuing research and development on the HD line platforms would ultimately result in advances justifying the release of a product line-up that substantially extends the sonic envelope of the HD line.

The latest products to bear the appellation "Reference" are the Reference PREAMP, Reference DAC and Reference AMP. The Reference DAC is the digital flagship of that family — the converter Nagra builds when there are no commercial compromises left to make. It draws on every lesson learned from the HD DAC X platform, the Reference PREAMP architecture, and the company's parallel work on the Reference Turntable, Reference MC Cartridge, and HD PHONO. What emerges is a converter that makes recorded music sound natural, deep, and alive, whatever the format.

The Reference DAC is built around a dual-chassis architecture — one chassis dedicated to the audio signal section, a second chassis dedicated to the digital section, with all controls, relay switching and home-automation logic isolated on their own supplies. Inside the audio unit sits a new generation of high-voltage power supplies generating the 200 V DC grid tension that drives the analog stages, with super-cap reservoir capacity providing the kind of instantaneous current delivery that battery-fed designs aspire to. Custom-made capacitors selected over months of listening sit at every critical node in the signal path. Mechanical damping has been refined with the addition of a phenolic layer inside the top cover, lowering the noise floor that a sensitive valve-output converter is otherwise vulnerable to. The Reference medallion above the Nagra modulometer identifies the unit as part of the Reference family.

Connectivity is what the customer at this tier expects. Digital inputs include AES/EBU, two S/PDIF, two NAGRA-LINK ST-1 optical for native compatibility with the wider Nagra digital ecosystem, an additional optical input, and an audio-grade USB UCA2 port. Analog outputs are provided on a single stereo XLR balanced pair and a single stereo RCA pair at a 1.5 V RMS reference level with output impedance below 200 ohms. The frequency response is essentially flat from 5 Hz to 40 kHz, crosstalk exceeds 110 dB at 1 kHz, and noise sits at –128 dBr unweighted at the reference output level. Remote automation, RS232 home-automation control, and the full suite of Nagra's integration conventions are present and accounted for.

The Reference DAC is best understood as the digital partner to the Reference PREAMP and Reference AMP — the three-component statement on which the rest of a reference-tier two-channel system is built. It is a flagship-class component and an audition is the conversation; we are happy to set one up at either showroom.

Main Features

• Dual-chassis architecture: one chassis for the audio signal section, one chassis for the digital section, with separate supplies for controls, relays and home automation
• New-generation high-voltage power supplies inside the audio signal unit, generating the 200 V DC grid tension
• Super-cap reservoir capacity added to the power supplies for instantaneous current delivery
• Custom-made capacitors throughout the audio signal path, selected by extensive listening
• New mechanical damping with the addition of a phenolic layer inside the top cover
• Reference medallion above the modulometer, identifying the unit as part of the Reference family
• Designed and manufactured by Audio Technology Switzerland

Specifications

Digital inputs: 1× AES/EBU; 2× S/PDIF; 2× NAGRA-LINK (single-mode ST-1 optical); 1× Optical; 1× Audio USB (UCA2)

Analog outputs: 1× stereo RCA; 1× stereo XLR (balanced)

Output level: 1.5 V RMS

Output impedance: < 200 Ω

Noise: –128 dBr @ 1 kHz, 1.5 V (unweighted)

Distortion: < 0.02% @ –20 dBfs; < 0.005% (H2 filtered) @ –3 dBfs

Frequency response: 5 Hz – 40 kHz, +0 / –1 dB

Crosstalk: > 110 dB @ 1 kHz; > 100 dB @ 20 kHz

Inter-channel phase: < 0.05° @ 1 kHz; < 0.3° @ 20 kHz; < 0.5° @ 50 kHz

Remote automation: 1× 3.5 mm input + 4× 3.5 mm relay outputs

Home automation: SUB-D9 RS232 (115200 baud)

Power consumption: 170 W max

Mains options: 100 V / 115 V / 120 V / 127 V / 230 V / 240 V (±10 %, 50–60 Hz; not user-adjustable)

Operating temperature: +15 °C to +35 °C

Operating environment: indoor only, IP30

Dimensions (each chassis): 433 × 436 × 121 mm (17.05 × 17.17 × 4.76 in)

Weight: 16.5 kg (36.4 lb) power-supply chassis; 13.5 kg (29.8 lb) audio chassis

Designed and manufactured by: Audio Technology Switzerland

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