C1 Digital to Analog Controller (legacy)

We describe the C1 as a Controller because it is more, much more than just a digital to analog converter. While creating a world-class DAC could be considered a sufficient challenge on its own, the use of modular component architecture and the power of sophisticated software control opens up opportunities as well as offering solutions: opportunities that transform the role, capabilities and versatility of the C1.

“Neutral, exciting, fast, tons of detail, yet musical in a way that is honest to the source, not gussied up with bloom and decay trails, it is not like the audio we grew up with. This kind of sound did not exist until now. As far as I’m concerned, CH Precision is at the forefront of digital technology. They are the leader of the pack.”


C1 Digital to Analog Controller

Of course, it is digital conversion that lies at the heart of the C1. The perfect preservation of time and amplitude information is critical to reproducing musical signals stored in digital format. Noise and jitter performance is central to the design of any high-performance DAC, but at CH Precision we believe that the solutions we have adopted for the C1 take digital performance to a whole new level. We have paid extraordinary attention to the master clock arrangements (as well as providing highly developed clocksync and external reference clock options) to minimize timing error to unprecedented levels, while our proprietary Polynomial Equations to Enhance Resolution (CH-PEtER) processing delivers incredible sample-to-sample resolution.

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Standard Inputs

  • Factory fitted with CH-Link HD, AES/EBU, S/PDIF and TosLink digital inputs
  • The CH-Link HD interface allows for synchronized transfer of high definition audio content (up to 32bit/768kHz) and DSD, offering the ideal interconnection to the D1 CD/SACD Transport or other CH-Link HD equipped units
  • Standard digital inputs accept PCM to 24bit/192kHz, DSD 1bit/2.822MHz (DSD64)

Optional Digital Inputs

  • The C1 can accept up to three digital input boards to allow multiple digital sources to be connected
  • Ethernet audio streaming input board, UPnP/DLNA compatible, allows connection to audio servers (NAS drives), streaming services and internet radio
  • PCM to 32bit/38 kHz
  • DSD 1bit/2.8224MHz (DSD64), 5.6448MHz (DSD128) or 11.2896 MHz (DSD256)
  • Native DSD and DoP
  • WAV, AIFF, FLAC, ALAC, AAC and MP3 formats supported in PCM
  • DSF and DFF formats supported in DSD
  • Asynchronous USB audio input board – PCM to 24bit/384kHz, DSD 1bit/5.6448MHz (DSD128, DoP encoded)

Digital to Analog Conversion

  • Four PCM1704 R-2R converters per channel
  • Fully complementary, dual mono symmetrical circuit topology
  • Discrete dedicated regulated linear power supplies for low noise and maximum channel separation


  • Independent 2.4GFLOPS DSP engines for each channel
  • Proprietary CH-PEtER synchronous data over-sampling processing
  • DSD to 705.6kHz PCM conversion
  • Resolution enhancement of audio material recorded at less than 24bits
  • Digital to Analog converters data scrambling
  • Linearization of the R-2R converters through on-board calibration process

Timing & Clocking

  • Ultra low jitter digitally controlled VCXO oscillators with dedicated power supplies
  • Optional master/slave Clock-Sync board allows synchronization with external clocks when used with the D1 CD/SACD transport, I1 Universal Integrated amplifier or computer-based audio source
  • Clock-Sync board also allows use of the T1 10MHz Time Reference clock

Volume Control

  • By-passable 0.5dB step hybrid volume control, coarse steps using relays and a resistor ladder and fine steps in the digital domain, to maximise system resolution

Analog Input Board

  • Discrete, fully differential analog input circuit
  • Balanced XLR and single-ended RCA inputs
  • 6V RMS maximum input level
  • Input offset and balance user selectable

Analog-to-Digital conversion

  • DSD 1bit/5.6448MHz (DSD128) direct conversion

Analog Output Stage

  • Pure class A, fully symmetrical circuit
  • Fully discrete, ultra low noise, high slew rate design
  • Zero global feedback
  • One pair each – balanced XLR, single-ended RCA and BNC outputs
  • DC coupled
  • 5.4V RMS maximum output (balanced XLR), 2.7V RMS maximum output (single-ended RCA/BNC)
  • Switchable absolute phase
  • Channel balance in 0.5dB steps


  • 480 x 272 pixel, 24bit RGB AMOLED
  • 15 standard, user-selectable text colors
  • User definable RGB option for text color

Remote Control Options

  • Infrared Remote Control handset for basic functions

Optional Hardware

  • Digital Input Board – CH-Link HD, AES/EBU, S/PDIF and TosLink
  • Network Player Input Board
  • Asynchronous USB Input Board
  • Clock-Sync Board
  • Analog Input Board – one pair balanced XLR, one pair single-ended RCA
  • Fully compatible with X1 External Power Supply
  • Compatible with T1 10MHz Time Reference external clock (with Clock-Sync board)

Technical Specifications

Conversion type
Linearized R-2R, 4x PCM1704 per channel
24 bit / 705.6kHz & 768kHz

DSP processing
CH-PEtER upsampler, synchronous, DSD to PCM
conversion and resolution enhancer

Full scale analog outputs level
5.4V RMS balanced
2.7V RMS single-ended

Signal to Noise Ratio
> 120dB

Total Harmonic Distortion + Noise
< 0.001%, full scale, 22kHz BW

440 x 440 x 133mm (W x D x H), 20kg per unit

C1 Specific Downloads