Cyrus DAC X+

Technical Information

Many Cyrus owners recollect the impact that the hi-fi industry felt a decade ago when Cyrus launched the Discmaster/Dacmaster/PSX-R combination. The combination set new performance standards for CD replay, featuring leading edge digital technology presented in a unique 4-box format.

The brief for the DAC X+ was to bring this 4-box formula up to date by taking the best DAC technology available today and building a class-leading stereo digital decoder to partner the CD XT SE+ and a pair of PSX-Rs. Adding a separate analogue pre-amplifier into the DAC X+ chassis upgrades the DAC X+ to the DAC XP+ which becomes the control centre for a high-end stereo system.

D/A Conversion: At the heart of a quality D/A converter is the circuit that converts the digital source signals to analogue. Careful design of this circuit is essential to retrieve the true dynamics of the source signal and to minimise undesirable artefacts such as noise and distortion. The DAC X+ achieves this with a two stage up-sampling design where all sources are initially up-sampled to 192k before analogue conversion by quad high-precision 24-bit converters operating in a fully balanced configuration. The technical specifications endorse the quality of this stage with class-leading performance for THD and noise. The elevated 192k sample rate permits our designers to use far less aggressive analogue filtering techniques to remove undesirable out-of-band digital noise.

Jitter reduction: All audiophiles understand that low jitter is an essential requirement for the clocks and data signals passed within a D/A converter. In the DAC X+ the sophisticated re-clocking circuit measures the precision of incoming digital signals to determine the quality of the input source. High accuracy sources such as the CD XT SE+ CD transport are digitally re-clocked by a close tolerance circuit with triple quartz references. For signals from low accuracy sources such as personal computers the circuit automatically relaxes the re-clocking precision to ensure reliable signal recovery.

Sample rate handling – The DAC X+ is prepared for the wide range of sample rates available from today’s digital sources and beyond. Group 1 close tolerance performance is available for 32k, 44.1 k, 48k, 64k, 88.2k, 96k, 128k, 176.4k, 192k source material. For sources outside of Group 1 requirements, any sample rate in the range 32k – 192k is accepted. Non-stereo waveforms (surround sound etc) are identified and suppressed to avoid undesirable digital noise.

Digital output: An optical digital output provides a useful digital feed to send the signal from the selected source to digital recording devices or to a multi-channel surround sound decoder.

Power supplies: The DAC X+ power supply is a traditionally built linear design, with an oversize toroidal power transformer including twin windings dedicated to the digital and analogue sections and entirely separate power regulation for the DAC and analogue filter sections. Two-stage regulation is used for critical stages with remote shunt regulators located within the heart of the audio circuitry.

DAC XP+ upgrade: By returning the DAC X+ to the factory, a complete high-end pre-amplifier stage with separate power supply can be added, bringing the DAC X+ up to full DAC XP+ specification.

Electrical
Digital Inputs - 6 SPDIF (4 coaxial, 2 optical)
D/A Outputs (unbalanced) - Fixed level stereo line output (via RCA jacks)
D/A Outputs (balanced) - Dual balanced (XLR jacks)
Power Supply - 75VA toroidal transformer
Communications - MC-BUS™ System BUS

Specifications
Digital Input - 500mV pk-pk 75 Ω
Digital Output - 500mV pk-pk 75 Ω
Sample rate tolerance - +/-1 00ppm of 32/44.1 /48kHz and multiples to 192k
Sample rate tolerance (wide) - Any sample rate in range 32k – 192k
Unbalanced Output - 2.3V 47 Ω
Balanced Output - 4.4V 47 Ω
THD+N - 0.002% (ref 0dBFS)
S/n ratio - 11 5dBA
Dimensions - (H x W x D) 73 x 215 x 360 (mm)
Finish – Quartz Silver and Brushed Black
Weight - 3.8kg