C1 Digital to Analog Controller User Manual
Dear Client, We are honored that you have chosen the CH C1 Digital to Analog Controller. Our team has put all his efforts into designing and manufacturing this top quality versatile and future-proof product and is proud to present it to you. We hope your C1 will bring you uncountable hours of emotion from your musical collection. But before starting your musical journey, we kindly ask you to pay attention to the information contained in this manual.
FCC-Notice Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
Table of contents 1 Technical Highlights.............................................................................................................................................................. 8 1.1 Digital to analog conversion......................................................................................................................................... 9 1.1.1 Clock management.....................................................................................................................
3.3.6.2 BNC clock outputs..................................................................................................................................... 25 3.3.7 Power cord receptacle and voltage selection....................................................................................................... 25 3.3.8 External power supply connector....................................................................................................................... 25 4 Operation.......................
1 Technical Highlights CH products are proudly designed and manufactured in Switzerland by CH Precision Sàrl. Our engineers have put all their knowhow into bringing you the C1, a top performances future-proof digital to analog (D/A) controller, based on slot-in boards and USB flash-drive firmware update. In its base version the C1 is a four inputs D/A converter, with integrated preamplifier functions such as source selection and volume control.
(4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) Power supply section Main power transformer Standby power transformer (ensures green mode Standby) Power supply regulation board AMOLED display (on front panel) Audio in, clock in/out, USB (firmware update) and RJ-45 (control/network) connectors (from slot-in boards).
The 4.8GFLOPS DPS engine used for each channel performs several tasks, including synchronous up-sampling (to 705.6/768 kHz), DSD to PCM conversion (for DSD layer playback of SACDs), volume control, resolution enhancement and linearity enhancement (proprietary scrambling algorithm). 1.1.3 D/A conversion stage The digital to analog conversion stage of each channel is handled by four Burr-Brown PCM 1704 R2R chips.
Volume control is achieved by a combination of analog attenuators and high resolution digital multiplication. When the volume is set in the range -95.5 dB to -12.5 dB, a 12 dB analog attenuator in engaged, and the DSP attenuates (i.e. multiply the audio sample in 32 bits floating point resolution) by [volume + 12 dB]. When the volume is set between -12.0 dB and -6.5 dB, a 6 dB analog attenuator in engaged, and the DSP attenuates by [volume + 6 dB].
• ANALOG_IN: provides single-ended RCA and balanced XLR analog audio input • SYNC_IO: provides advanced clock synchronization options (1 clock in, 2 clock out) • CONTROL: provides a USB port for software upgrade and an Ethernet port for command • NETWORK: optional board used to upgrade the CONTROL board slot. Provides a USB port for software upgrade and an Ethernet port for high resolution audio streaming and command There are five slots in the C1.
+/- 2.5 us), tracking below 0.1 Hz with 0.1 PPM corrections for optimal jitter rejection. Two 75 Ohm Wordclock outputs completes the input/output capabilities of the SYNC_IO board. When C1 is matched with a D1, both equipped with a SYNC_IO board, the optimal configuration is to set the C1 as the clock master (C1 clock source: INTERNAL), and D1 as the clock slave (D1 clock source: SYNCHRO BNC 75).
2 Before Use Please read the following carefully. 2.1 Package content Make sure that the package content is complete. If not, please contact your authorized dealer.
• Do not install in direct sun light or near any heat source such as radiators or other apparatus generating heat • Do not install in a confined space and make sure sufficient air can flow around the unit • Do not operate under high ambient temperature (>40°C) or with extremely high humidity such as in humid cellars • Only use options and accessories specified or recommended by the manufacturer • Do not open the unit nor try to service it by yourself.
vibrations during transport may cause the adjustment spikes to move from their fully retracted position. There is risk of scratching the installation base if the spikes are not fully retracted when installing the unit. 2.6 Cleaning Use a soft, dry towel or cloth for cleaning. Never use any solvent or liquids as they may damage the surface treatment or penetrate inside the unit. 2.7 Maintenance and service The C1 D/A controller contains no user serviceable parts.
3 Installation 3.1 Unpacking Unpack the C1 D/A controller and store the packaging for future transportation. Be careful when lifting the C1 as the unit is heavy (over 20kg). Get someone to help you if necessary. When unpacking and installing the C1, take care not to damage the high quality surface treatments. 3.1.1 Removing the security screw The transformer base plate must be secured during transportation to avoid damage to the isolating silent blocks.
When the spikes are fully retracted, the C1 sits on elastomer rings to protect the base. If the base on which the C1 is located is fragile or should not be scratched, please make sure to use the optional CH support discs to protect the base. ( 1) ( 1) ( 2) ( 2) ( 2) ( 2) ( 3) ( 1) ( 3) ( 3) ( 1) ( 3) ( 4) Adjustment shafts, feet and spikes (1) (2) (3) (4) Adjustment shafts.
3.3 Connections This section provides information about how to connect your C1 D/A controller to your system. As the C1 is a modular design with different optional boards, the description applies to the example configuration presented below. If your options do not match the example or you don't feel secure with the connections to be applied to your configuration, please contact your authorized dealer for assistance.
(19) (20) (21) (22) (23) (24) (25) (26) (27) USB port for software upgrades. [CONTROL board or optional NETWORK board] CH Link digital input [DIGITAL_IN #1 board] Coaxial (S/PDIF) digital input [DIGITAL_IN #1 board] RCA single-ended analog input for right channel [optional ANALOG_IN board] XLR balanced analog input for right channel. [optional ANALOG_IN board] Analog ground connector 2 Analog ground connector 1.
3.3.1.1 USB port The USB port on the CONTROL board is dedicated to the firmware update of the C1 unit. Do not use it for any other purpose. For more information on unit firmware update, please refer to the corresponding section of this manual. 3.3.1.2 Ethernet port The Ethernet port on the CONTROL board is dedicated to network based control of the unit. This functionality is currently not implemented, thus leave the Ethernet port unconnected. A future C1 firmware release will provide this functionality.
DIGITAL_IN boards back panel layout 3.3.3.1 Standard digital inputs Each DIGITAL_IN board provides three standard digital inputs: AES-EBU (carrying consumer encoding), Coaxial (S/PDIF) and Optical (TOSLINK). Audio format supported are 16 or 24 bits, 44.1, 48, 88.2, 96, 176.4, 192 kHz sampling frequency. 3.3.3.2 CH Link digital audio interface Each DIGITAL_IN board includes a CH Link proprietary digital audio interface. This interface carries both complete audio stream and control information.
Microsoft Windows (XP, Visa, 7 and 8) so far only supports USB Audio Class 1.0 by default, limiting the playback to 24bit/96kHz files. Installing the driver provided with optional USB_IN board enables MS Windows computer to support USB Audio Class 2.0, thus allowing 24bit/192kHz files playback. DSD files need USB Audio Class 2.0 to be active and they are packed into a 24bit/176.4kHz PCM-like signal for bitstreaming. The C1 supports the DSD over PCM (DoP1.
ANALOG_IN panel layout 3.3.6 SYNC_IO board The SYNC_IO board is an optional clock synchronization board to be used with an external clock generator or together with other CH products, such as the D1 SACD/CD unit. The board provides one clock input and two clock output on BNC connectors. Each VCXO digital PLL (one is based on a 22.5792 MHz Masterclock and the other one on a 24.576 MHz Masterclock) of the C1 is capable of frequency and phase locking. The frequency is tracked below 0.1 Hz with 0.
3.3.6.2 BNC clock outputs Two 75 Ohm output clock connectors are also provided on the SYNC_IO board. Use one of these connectors to synchronize an external device to your C1. Output clock is either a buffered version of input clock (if C1 is synchronized to it input clock), or current audio Wordclock (if C1 is clocked by its internal high precision oscillator). 3.3.
4 Operation The C1 D/A controller is operated either from the front panel or from the IR remote control. Feedback to the user is provided by a high-definition AMOLED display with customizable colors. Setup operations are exclusively handled from the front panel. 4.1 Front panel controls 4.1.
knob for 2s or more. ( 1) ( 4) ( 2) ( 5) ( 3) User control knob movements (1) (2) (3) (4) (5) External ring rotate Left [<
4.2 Operating modes The C1 D/A controller has two main operating modes: Normal mode and Menu mode. Normal mode is used to access standard preamplifier controls whereas Menu mode is used to configure the unit. The C1 also includes Shortcuts for quick access to selected Menu mode items. Shortcuts are user programmable and most Menu mode items can be selected as Shortcuts. 4.2.1 Normal mode Normal mode is used for standard preamplifier functions. When powered-on, the C1starts in Normal mode.
Displayed elements depend on the installed optional boards and user settings. In the example above, C1 is playing the audio coming from its first AES-EBU input at the rate of 44.1 kHz, over-sampling it to 705.6 kHz (x16). The output level is -18.5 dB, but is currently muted. C1 has locked its 22.5792 MHz (512 x 44.1 kHz) VCXO to the incoming audio stream. The polarity of the audio signal is inverted, and the C1 is powered through its external DC power supply.
[LP] Long Push Any state As in Normal mode [C>>] Central Rotate Right Shortcuts (except last) Last Shortcut (SETUP) Modify parameter up (when available) Enter Menu mode [<>] External Rotate Right Shortcuts (except last) Last Shortcut (SETUP) Modify parameter up (when available) Enter Menu mode [<
(1) DETAILED SETUP EXIT (2) C ENTER (3) (4) SETUP Shortcut display elements (1) (2) (3) (4) Shortcut title. It indicates that Detailed Setup (Menu mode) can be entered at this stage Current value of the parameter. Default action is to exit (go back to Normal mode) Arrow indicating External Rotate Right [E>>] (or Central Rotate Right [C>>]) Next parameter value. If External Rotate Right [E>>] is applied, the unit enters into Menu mode 4.2.
Following illustration shows the elements of a the C1 SETUP Menu page, the entry point to the C1 menu structure. (1) C1 SETUP AUDIO SETTING DISPLAY SETTING SHORTCUTS FACTORY SETTING FACTORYSETTING INSTALLED OPTIONS NETWORK > Mute Phase polarity Clock source Active input Input gain C (3) (2) C1 SETUP menu display elements (1) Menu title. When entering a menu item, the title also shows the parent menu. If the AUDIO SETTING menu is entered, the title line would display C1 SETUP >> AUDIO SETTING.
(1) Menu title. C1 SETUP >> AUDIO SETTING shows that the parent menu is C1 SETUP. By applying External Rotate Left [<
4.3 Configuration Configuration of your C1 D/A controller is accomplished by setting parameters in the Menu mode (see previous section for how to access Menu mode and how to navigate menu items). Following diagram shows the complete menu structure (terminal items not show). Grayed menu items are items which depend on installed optional slot-in boards.
There are six main menus used for configuration of the C1: • AUDIO SETTING: Allows to adjust audio related parameters • DISPLAY SETTING: Allows to adjust display related parameters • SHORTCUTS: Allows to assign and modify Shortcuts for user interface customization • FACTORY SETTING: Indicates the software version and allows to update it.
Unmuted PHASE POLARITY In phase Out of phase None None CLOCK SOURCE (individually selectable for each input) Audio In SYNC_IO board to Internal Clock choose some of these Synchro BNC (75 Ohm) clock sources Synchro BNC (Hi-Z) SRC Audio In clock source is available in all cases for digital in board inputs. SRC adds an asynchronous sample rate converter stage that allows the C1 to lock even on S/PDIF sources that do not comply with AES requirements.
DSD FILTER TYPE Minimum Phase Linear P. apodising Linear P. sharp None None Choice of different filter types for DSD audio input. C1 TYPE D/A Controller D/A Converter Connected to power amp When C1 is configured as D/A Converter, its output Connected to preamp volume is not attenuated (0dB).
4.3.1.2 DISPLAY SETTING The C1 SETUP >> DISPLAY SETTING menu allows configuration of the display related Parameters of the unit.
BRIGHTNESS DSD COLOR DSD 10% 20% 30% ... 90% 100% None Predefined colors Custom color Edit custom color None Sets the display brightness when a DSD audio stream is played. The C1 supports three different display settings (BRIGHTNESS and COLOR parameters). One used during PCM playback, one used during DSD playback and one used when playing an analog source Selects the display color for DSD playback Predefined colors represents a set of factory defined colors Custom color is a user definable color.
4.3.1.3 SHORTCUTS The C1 SETUP >> SHORTCUTS menu allows configuration of the Shortcuts. Accessible Parameters are: - SHORTCUT1: Defines action for Shortcut #1 - SHORTCUT2: Defines action for Shortcut #2 - SHORTCUT3: Defines action for Shortcut #3 - SHORTCUT4: Defines action for Shortcut #4 - SHORTCUT5: Defines action for Shortcut #5 - SHORTCUT6: Defines action for Shortcut #6 Note that unused Shortcuts are not displayed. The first available (e.g.
4.3.1.4 FACTORY SETTING The C1 SETUP >> FACTORY SETTING menu allows to get information about current C1 firmware version, to update the C1 firmware, to reset the unit to default configuration (or subset of setting), and to calibrate the DAC stage.
control sends by default). When 'None' is selected, the C1 cannot be controlled by a remote control anymore. CALIBRATE Start calibration C1 should be warmed-up Launch automated calibration left and right channel DAC stage. It takes about 40s per channel to complete. For optimal performances, please make sure the C1 is warmed-up (i.e. turned on for more than an hour) before running calibration.
4.3.1.6 NETWORK The C1 SETUP >> NETWORK menu allows knowledge and customization of the network related Parameters of the unit.
4.4 Remote control 4.4.1 Remote control operation The C1 controller is delivered with an IR remote to control the unit's basic operations. The provided remote control is not intended to be used to configure the unit.
NEXT INPUT (6) Select next enabled input Phase inversion PREVIOUS INPUT (5) Select previous enabled input Phase inversion Remote control functions 4.4.2 Changing the remote control batteries If the LED does not turn on when pressing a button of the remote, it is likely that the remote batteries need to be changed. To replace the batteries, remove the back cover of the remote control by removing the screws (M2.5 cross-shaped type, make sure to use appropriate screwdriver).
D1 SACD/CD Drive, default setup (1x DIGITAL_OUT) CH-LINK Cable C1 D/A Controller, default setup (1x DIGITAL_IN) Simple D1 - C1 connection More generally, when a C1 has no SYNC_IO board, it can only clock itself to the incoming audio stream (clock source is AUDIO IN) when playing a CH-LINK, AES EBU, COAXIAL or OPTICAL input. The same applies for multichannel setup when CH products have no SYNC_IO board.
D1 SACD/CD Drive, 1x DIGITAL_OUT + SYNC_IO CH-LINK Cable 75 Ohm BNC coaxial cable C1 D/A Controller, 1x DIGITAL_IN + SYNC_IO D1 - C1 connection when SYNC_IO equipped When paired with a hybrid configured D1 (DIGITAL_OUT L/R + ANALOG_OUT Ls/RS and C/Sub), recommended setup is still the same (i.e. clock goes from C1 to D1 to have optimal conversion condition for main channels). In such case: • D1 clock source: SYNCHRO BNC 75 Ohm • C1 clock source (for this input): INTERNAL 4.5.
D1 SACD/CD Drive, 3x DIGITAL_OUT (L/R + Ls/Rs + C/Sub) + SYNC_IO CH-LINK Cable CH-LINK Cable CH-LINK Cable 75 Ohm BNC coaxial cable 75 Ohm BNC coaxial cable 75 Ohm BNC coaxial cable L/R C1 D/A Controller, 1x DIGITAL_IN + SYNC_IO Ls/Rs C1 D/A Controller, 1x DIGITAL_IN + SYNC_IO C/Sub C1 D/A Controller, 1x DIGITAL_IN + SYNC_IO Multichannel D1 - C1 connection when SYNC_IO equipped In such case: 48 • D1 clock source: SYNCHRO BNC 75 Ohm • L/R channels C1 clock source (for this input): INTERNAL •
• C/Sub channels C1 clock source (for this input): SYNCHRO BNC 75 Ohm 4.5.5 C1 D/A controller + Computer (USB audio) When a C1 equipped with a USB_IN board is used together with a computer for audio files playback, a single link is in place between them: a type A (computer side) to type B (C1 side) USB 2.0 cable. But this single link enabled data to flow from the computer to the C1, while the C1 give the pace of the data transfer, thus being clock master.
Tablet Wifi Computer with LAN capability (e.g. NAS server) Clock Audio Ethernet RJ45 cable Router Audio Clock Ethernet RJ45 cable C1 D/A Controller, 1x DIGITAL_IN + 1x Ethernet NETWORK board C1 connection to home network In such case: • C1 clock source (for this input): INTERNAL 4.6 Returning to Factory defaults The unit can be reset to Factory default settings by using the RESET ALL SETTING item of the FACTORY SETTING menu.
5 Firmware update 5.1 Introduction The C1 D/A Controller is built around multiple programmable circuits. This approach allow the unit to be updated to support new features. It includes a host micro-controller, a display controller, several FPGAs (Field Programmable Gate Arrays) and DSPs (Digital Signal Processors). When optional boards are added, even more programmable circuits are in use inside your C1.
5.2.2 Updating the firmware (Firmware Update procedure) Once the USB stick is ready with the appropriate files, the effective firmware update can be engaged. To do so, follow the steps of the Software Update procedure: 1. Connect the USB stick to the A-shaped USB port of the CONTROL board at the rear of your C1 unit. 2. Turn the unit on if it is in standby or powered-off. Navigate to the C1_SETUP>>FACTORY_SETTING menu and select the UPDATE_FIRMWARE item. 3.
6. To verify that the Emergency Firmware Update was effective, navigate to the C1_SETUP>>FACTORY_SETTING menu and select the FIRMWARE_VERSION item. Check that the displayed firmware version number matches the version number of the firmware update used for the Emergency Firmware Update procedure. Note: The Emergency Firmware Update process can last several minutes, do NOT interrupt it! If the Emergency Software Update procedure fails, try to download the latest software images from www.ch-precision.
6 Troubleshooting Error Action No power Check the AC power cord Check the power button at the back of the unit Check the mains fuse on the AC power cord receptacle Remote control does not work Check if the unit is connected to the AC wall outlet and powered-on Check if distance is not too far to the C1 unit. Get closer and try again.
records. it. In this case, use a subsonic filter of decrease the gain of the phono stage. Lost in the settings? Restore factory setting and start your setup again Firmware update fails Try Emergency Software Update procedure If it fails, download the latest C1 firmware from www.ch-precision.
7 Specifications 7.1 Specifications General Supported audio formats Standard digital inputs (AES-EBU, coaxial and optical): - Stereo S/PDIF encoded PCM; 16 to 24 bits; 44.1, 48, 88.2, 96, 176.4 or192 kHz CH-Link: - Stereo I2S PCM; 16 to 32 bits; 44.1, 48, 88.2, 96, 176.4, 192, 352.8 (DXD), 384 (DXD), 705.6 or 768 kHz - Stereo cyphered DSD 1bit; 2.8224 or 5.6448 MHz USB (audio class 1.0): - Stereo PCM; 16 to 24 bits; 44.1, 48, 88.2, 96 kHz USB (audio class 2.0): - Stereo PCM; 16 to 24 bits; 44.1, 48, 88.
Frequency response (-3dB point) DC-120kHz (balanced and unbalanced, digital filter dependent) Dynamic Range (DNR) 120dB (balanced and unbalanced) Signal to Noise Ratio (SNR) 123dB (balanced and unbalanced) Total Harmonic Distortion + Noise (THD+N) <0.0015% (balanced and unbalanced) Digital Audio inputs (DIGITAL_IN board, four stereo inputs per board) CH LINK Proprietary high-definition link supporting high-definition uncompressed audio and control.
Clock output 2x BNC connectors, 2Vpp, 75'Ohm output impedance Buffered Clock input or Audio Wordclock 50% duty cycle square wave Remote control Remote control type Infrared. Uses RC5 codes. Range: 10m (line of sight) Remote control batteries 2x AAA type Specifications Design and Specifications are subject to change without notice Weight and dimensions are approximate Illustrations are informative only and may differ from actual production models Casing design by Mana Ishoni 7.
7.
CUSTOM COLOR DSD VFD like BRIGHTENESS ANALOG 80% COLOR ANALOG Blue CUSTOM COLOR ANALOG VFD like INPUT RENAMING CH-LINK 1 / 2 / 3 AES EBU 1 / 2 / 3 COAXIAL 1 / 2 / 3 OPTICAL 1 / 2 / 3 USB 1 / 2 STREAMING ANALOG XLR 1 / 2 ANALOG RCA 1 / 2 SHORTCUTS SHORTCUT1 MUTE SHORTCUT2 PHASE POLARITY SHORTCUT3 None SHORTCUT4 None SHORTCUT5 None SHORTCUT6 None Factory settings 60 C1 User Manual Rev 1.
Rev 1.
CH Precision Sàrl ZI Le Trési 6D CH-1028 Preverenges SWITZERLAND www.ch-precision.com info@ch-precision.com Made in Switzerland 62 C1 User Manual Rev 1.
