Outboard DACs

This combined DAC and headphone amplifier from NuPrime has an impressive range of features that will suit both studio professionals and high-end audiophiles alike. It has full microprocessor control with memory retention and low-noise JFETs are used in the input stage to offer a very low noise floor.

The DAC-9X has an analogue stereo input alongside a USB-A extension port, USB-B, optical, coaxial and two IIS/DSD inputs. At the other end, it offers standard RCA unbalanced stereo and XLR balanced outputs, an optical out and a 6.35mm standard stereo headphone jack. The DAC decoding supports PCM up to 384kHz, DSD256 and MQA. The DSD supports native playback by ASIO2.1 and DoP method.

The preamp section is capable of driving a power amplifier as well as the internal headphone amp. In addition, there is individual volume adjustment on each input for precise source level matching. The internal power supply utilises a toroidal mains transformer together with a low-noise power supply, which has been given an anti-vibration treatment to keep hum to a minimum.

The internal DAC is built around dual ESS Technology 32-bit audio ESS9028Q2M chips, which independently decode left and right channels. NuPrime’s SRC IC chip, which has been co-developed with IC vendor to provide DSP processing, is also included. The input signals are up-sampled to megahertz rates before being down-converted to the targeted sampling rate in an effort to minimise jitter and distortion.

The LED on the front panel glows green to indicate it is decoding and playing an MQA stream, and blue when playing an MQA Studio file directly. A magenta glow highlights that the unit is rendering an ORFS (original sample rate) format MQA stream or file and yellow denotes DSD format.

The front panel numeric display shows the DSD sample rate, PCM sample rate or volume level (0-99). The DAC-9X features asynchronous data transfer mode and very low power consumption in standby. A remote is included and the NuPrime comes in black or white finishes.

Sound quality
To test the DAC-9X as a headphone amplifier, I use Sennheiser’s HD 800 dynamic headphone fitted with a Nordost Heimdall 2 cable (HFC 440). First to audition is a recording of Schumann’s Piano Concerto in A minor performed by Sviatoslav Richter with the Monte Carlo National Opera Orchestra. The piano is reproduced very well and played with great precision. The performance is open and powerful, with an excellent and full bass response. The NuPrime takes the strings in its stride and there is no edginess during crescendos. Instrument imaging is excellent and there’s a very convincing soundstage.

Listening to the Syd Lawrence Orchestra playing Sing Sing Sing, the treble is clear and the trumpets are refined and not overly harsh. At the other end of the audio spectrum, the bass is tight and very well extended.

Next, I connect the DAC-9X to my system to use it as an external digital-to-analogue converter. Fed from the coaxial output of my PrimaLuna ProLogue Eight Mk.2 CD player, Gluck’s Italian Arias sung by Cecilia Bartoli sound superb with a wide and deep soundstage. Bartoli is positioned right in front of the orchestra, just as she should be.

Conclusion
The DAC-9X delivers very elegant and refined performances and is clearly a great match for high-quality headphones. Operating as either a headphone amp or a standalone DAC, the audio quality is really superb. This is a high-quality unit that will be very much at home in both the studio and more domestic environments. NR    

DETAILS
Product: NuPrime Audio DAC-9X
Type: DAC/headphone amplifier

FEATURES
● Supports: PCM up to 384kHz; DSD256
● 6.35mm headphone output
● Outputs: RCA; optical; balanced XLR