C10 Digital to Analog Converter

C10 Digital to Analog Converter

Like all 10 Series components, the C10 is a twin-chassis design, with separate audio and power supply boxes. Like all CH components it is modular, updatable, upgradable, expandable and future-proof. Like the C1.2 it is a fully differential design, uses a developed version of the proprietary PEtER Spline Filter algorithm and uses the same CH-LINK HD, proprietary high-res capable connection for native transfer of DSD, MQA and high-res PCM formats. But beyond that, it is all change, from the completely revised power supply and grounding arrangements to the improved practicality of the simplified upgrade path, from the physical layout of the chassis to the totally new DAC architecture. The C10 breaks new ground in terms of CH product design – and new ground in terms of musical performance.

The heart of any converter is the processing of digital data into analog signals. The C10 relies on the proven performance of the PCM 1704 R2R DAC chip, driven by our sophisticated DSP-based, short-tailed PEtER over-sampling algorithm. The DSP operates at 32bit fixed point, before conversion to 24bit at the output, the native resolution of the PCM 1704. But in the C10, we use 16 DACs in a dual differential, sequential DSQ™ Phase Array topology. In other words each phase of each channel has four dedicated DAC chips. The incoming data is fed to each chip in sequence, so that the first chip receives samples one, five and nine, the second chip samples two six and ten – and so on. It’s complex, it’s exacting and demands supreme precision from the clock and driving software. But the results are phenomenal. The powerful DAC in the C1.2 already achieves data output rates of 16x Fs (705.6/768 kHz): in the C10 that increases to 64x Fs (2.8224/3.072MHz)!

In order to achieve the super-quiet and interference-free environment necessary to achieve stable operation and maximise the benefits of these extraordinary processing rates, we have had to re-structure every aspect of the DAC’s electrical and physical topology. The C10 power supply provides four independent, highly regulated multiple DC feeds to galvanically isolated circuit blocks within the chassis: the digital processing circuitry, the clock and the left and right DACs. The audio chassis has adopted a mirror imaged layout, the modular input cards located centrally with the DACs disposed on either side and benefiting from symmetrical clock feeds. The low-pass filter, essential to eliminate spurious high-frequency output in any DAC, has been changed from combination first and second order slopes to a single, third-order Sallen-Key Bessel filter, reducing propagation error between 20Hz and 20kHz from nanoseconds to less than two femtoseconds! The analog output stages incorporate lessons learnt in developing the ultra-quiet P10 and L10, with their uninhibited dynamic response and resolution.

The C10 dispenses with the C1.2’s variable output and analog input options. This is a pure DAC, dedicated to delivering the best possible performance from digital storage media. Best performance demands pairing it with a top-flight line-stage pre-amplifier, like the L10. To optimize system matching, it offers user selectable output levels (1, 2.5 or 5V) and switchable local/global feedback. Inputs are still modular and configurable. The C10 is fitted with CH-Digital-IN HD and Ethernet Control cards as standard, providing connection to CH-LINK HD, AES/EBU (XLR), S/PDIF (RCA) and TosLink optical inputs and also allowing network control via the CH-Control App. The Ethernet Control card can be upgraded to the Ethernet-In HD card, creating a high-quality streaming interface (compatible with all major streaming services), while three additional slots allow users to fit an extra digital input card, a USB input and the Clock Sync card for connection to an external 10MHz master clock, such as the CH T10 Time reference.

The C10 Mono

Like the other 10 Series components – indeed, like all CH core components – the C10 is inherently upgradable/expandable. In the case of the C1.2, there is the option to move in stages from a single-box to a six-chassis solution! In the C10 we have opted for a simpler and more direct path. To move from the C10 to C10 Mono, you simply add an extra power supply. The separation of the circuit blocks within the C10 audio chassis, combined with the four discrete DC feeds from the power supply means that we can surpass the benefits of the six-box topology by adding a single extra power supply chassis, splitting the DC feeds between them. Same significant step up in performance – half the boxes to accommodate.

Same old story – whole new performance…

In many ways, the guiding principles that underpin the C10’s design are firmly rooted in the existing 1 Series. But the revised topology, the novel DSQ™ Phase Array DAC architecture and the incredibly sophisticated grounding and power supply arrangements deliver a whole new level of upgradable, configurable, musical performance. The 16 software-driven R2R DACs at the heart of the C10 mean that it is both updatable and future-proof: as future-proof as the C1.2 – still at the top of its game after 15 years. The C10 establishes a completely new standard for musical performance, practicality and versatility. It promises its owners a relationship that’s as long as it is musically rewarding.