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C1 Reference Digital to Analog Controller


Designed for the true music lover, the C1’s apparent simplicity hides highly sophisticated technological solutions with the single goal of recreating the full musical experience.

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Designed for the true music lover, the C1’s apparent simplicity hides highly sophisticated technological solutions with the single goal of recreating the full musical experience. This emotion can only be achieved when both level and time information are properly reconstructed from the digital data. And this is what the C1 is all about…

The C1 is based on a fully modular, future-proof architecture. Up to three inputs boards include standard digital inputs complemented by the proprietary CH-Link interface. Optional streaming audio inputs as well as line-level analog inputs enable the use of the C1 as a full featured preamplifier thanks to its integrated volume control.

A reference grade linear power supply (with <1W power consumption in standby mode), sophisticated mechanical chassis design and full USB based firmware update also contribute the C1’s uniqueness, for now and for any future format!



Up to three input boards allows the unit to include many input types. One digital input board is provided in base configuration, while two slots are kept free and can be fitted from factory or after product installation with the following board types:

  • digital input board (1x AES/EBU, 1x S/PDIF, 1x Toslink and 1x CH Link)
  • analog input board (1x XLR balanced and 1x RCA single-ended)
  • USB input (1x USB B-type)

The CH-Link interface allows for synchronized transfer of High Definition audio content and control over a single connection and is the optimal link between the C1 and the matching D1 SACD/CD drive. Audio data on CH-Link is cyphered when protected content is transmitted.

The ethernet streaming board option replaces the ethernet control board in order to add the C1 a uPnP/DLNA compatibe input. It should be noted that this input can be added even if the three available input slots are fitted.


For each channel a fully programmable 4.8GFLOPS DSP engine is used for the following processes:

  • proprietary CH-HiD processing for data over-sampling at 705.6kHz/768kHz
  • DSD to PCM direct conversion at 705.6kHz with selectable low-pass filters
  • resolution enhancement for data streams of less than 24 bits resolution
  • D/A converters data scrambling

This DSP engine also linearizes each of the four R-2R converters – its absolute output level as well as DC offset is taken into account – thanks to a calibration process which is done at factory but can also be performed by the user afterwards to maintain optimal operation over time.

Timing & clocking

Extreme care has been given to the timing of the audio conversion. The clocking section of the C1 is based on two ultra low jitter digitally controlled VCXOs to support synchronously every available audio sampling rates.

When equipped with the optional synchronization board, the C1 can be used with external clock generators or it can transmit the D1 SACD/CD drive a synchronization clock in order to slave it.

D/A conversion

The digital to analog converter boards are full dual mono with one board per channel. A dedicated set of regulated power supplies has been built for each channel in order to keep the channel separation at its maximum. Each channel is using four R-2R converter in a balanced design to create directly from the D/A conversion process an analog balanced signal.

Volume control

An integrated volume control is embedded into the C1, which can be turned off in case an external analog preamplifier is used. It has been done with a mix of analog and digital steps to ensure the best possible resolution at all listening levels. Coarse steps are done with relay-driven resistor-based dividers, while the fine steps are done into the DSP engine in floating point.

Analog stages

All analog stages inside the C1 are built only with discrete components, no operational amplifier have been used into these sections. This deliberate choice warranties the shortest path for the audio signal and allows the use of custom-made building blocks. All analog stages have the following features:

  • no use of global negative feedback
  • operating mode in pure class A
  • fully symetrical design

No capacitors have been used in the signal path to ensure the maximum transparency.