Singxer SU-6 USB Digital Audio Interface XMOS XU2008 CPLD Femtosecond Clock Interface

Singxer SU-6 USB Digital Audio Interface XMOS XU2008 CPLD Femtosecond Clock Interface

Description:
The SU-6 digital interface is a new generation of high-performance USB digital audio interface developed by the Singxer team.

It uses XMOS' latest xCORE-200 series and Xilinx's high-performance large-scale PGA chip.

The SU-6 is a digital interface using a thermostat-level clock system.

Crystek's two CCHD-957 femtosecond crystal oscillators provide a solid foundation for the superior audio signal quality of the SU-6 output.
 
The SU-6 digital interface uses a standard USB2.0 input interface, while the SU-6 has a rich output interface, including S/PDI for fiber/coaxial RCA and BNC outputs, AES/EBU for XLR balanced output, RJ45 and HDMI interfaces. Output I2S (including DSD ON signal), clock output supports MCLK main clock and WCLK word clock.

The power system design was optimized and the audio section was powered by a 7.5F (7.5 million uf) super capacitor.

SU-6 is a new generation of USB interface. It is located in the high-end interface. Compared with our products in the past, SU-6 mainly uses the following four new technologies independently developed:
1. Built-in CPLD pre-shaping technology and source synchronization technology based on FPGA reshape the isolated I2S signal, thus eliminating the additive jitter caused by the isolation chip.

2. The new design of the FPGA algorithm, built-in FIFO buffer data before output, SPDIF output using FPGA re-coding, so that coaxial output can support PCM 384K and DSD DOP128.

3. Using CRYSTEK’s CHD-957 high-performance femtosecond crystal oscillator, cooperating with self-developed constant temperature system and ultra-low noise supercapacitor power supply system, the short-term stability of the clock is further improved.

4. Unique single clock system, all the circuits of the whole machine are designed with synchronous clock. The USB clock is synthesized by PLL from femtosecond clock.

Technical Parameters:
Sampling Rates Supported by Output Interfaces:
- PCM: 44.1KHz, 48KHz, 88.2KHz, 96KHz, 176.4KHz, 192KHz, 352.8KHz, 384KHz
[I2S out and WCLK out support all sampling rates, S/PDI and AES/EBU support 384K, and optical fiber support 192K]
- DSD:
  2.8 MHz (DSD64) – DoP, native
  5.6 MHz (DSD128) – DoP, native
  11.2 MHz (DSD256) – DoP, native
  22.5 MHz (DSD512) – native
  [I2S out supports all DSD formats, S/PDI and AES/EBU support DSD128 DOP mode, and optical fiber supports DOP64 at the highest level]
- Bit Width: Up to 32 bit over I2S output; Maximum 24 bit over S/PDI, AES/EBU

Electrical Standards for Interfaces:
1. The USB input socket is a standard USB-B base with a power supply range of 4.5V-5.1V.

2. DC POWER input socket uses DC2.1 socket to support 7.5V-9V DC input (in order to realize the fast charging of supercapacitor, the power supply requirement is 3A).

3. The BNC interface and RCA interface output standard S/PDI signal with a level of 550 mV (connected to standard load) and an output impedance of 75 ohms. 24/384k and dsd128 over dop support (Dac must also support this, otherwise most dacs can accept 24/192 and dsd64 over dop)

4. The XLR interface outputs standard AES/EBU signals with a level of 3.3V (connected to standard load) and an output impedance of 110 ohms. 24/384k and dsd128 over dop support (Dac must also support this, otherwise most dacs can accept 24/192 and dsd64 over dop)

5. Word Clock (WCLK) output uses BNC interface, TTL (no load), output impedance is 75 ohms;

6.Two-channel HDMI-I2S signals are output through HDMI socket. The four output signals include MCLK, BCLK, LRCLK and SDATA signals. The standard differential level of LVDS is adopted and the impedance is controlled at 100 ohms. The PIN13-15 of HDMI socket is DSD_ON signal, the high level is I2S working in DSD mode, the level is LVTTL; the PIN18 is 5V weak power output (output current is less than 20ma), which can be used as interface plug-in indication; the I2S sequence of two output lines is the same.

7. RJ45-I2S output I2S signal is CMOS (5V) single-ended signal, low resistance output, output four signals including MCLK, BCLK, LRCLK, SDATA signal.

7.Fiber optic ports output standard optical signals. 24/192k support and dsd64 over dop.

Details:
1. Implement the design concept of electric power as the mother of sound, pay attention to the design of power circuit, adopt external DC input, built-in super capacitor power supply, with high performance, low noise and fast response LDO.The whole board is powered by up to 6 independent LDOs. The digital audio board is powered by a secondary LDO. The clock part even uses LT's ultra-low noise LDO, which lays a solid foundation for ensuring the ultimate performance of the output.

2. In order to ensure excellent electrical transmission performance, XLR sockets are made of Swiss Neutrik products, USB-B sockets are made of TE, and enthusiast BNC and RCA coaxial sockets are made for Taiwanese manufacturers. Even the fuses are selected from the United States. Litteluse model.

3. The audio board is designed with a 4-layer board to ensure a complete ground plane and power plane. High-speed digital design is used to ensure signal integrity and power integrity of the board. Special processing of the clock signal, using packet design and accurate impedance control, to ensure the signal quality of the clock and improve its anti-interference ability.

4.Input and output signals are in accordance with the standard design, especially the USB high-speed signal uses 90 ohm impedance control, also built-in anti-static TVS protection circuit; I2S signal uses LVDS differential level standard, impedance control is 100 ohms, 4 outputs are used A separate LVDS driver.

System Compatibility:
1. For Windows 7, Windows 8, Windows 10; 32/64 bit, need to install a dedicated driver
2. For Native MacOS 10.6 and above, using the system comes with a driver
3. For Native Linux with UAC2 compliant kernel, using the system's own driver, (tested on Ubuntu and Daphile systems, based on INTEL X86 platform)
4. ForAndroid OS 4.2 and above, the device needs to support OTG function. Generally speaking, it fits for Android 5.0 system by default, and for system below 5.0 it is to be used with a dedicated player.

HDMI -I2S Interface Output:
1. LVDS differential signal with a level of 3.3V;
2. DSD ON signal, 5V power supply (small current), the internal PGA of the MUTE signal has been processed, and the MUTE signal will not need to be output;
3. The DSD ON signal can be defined by itself. The DSD ON signal can be arbitrarily output to the PIN13, 14, 15, and 16 pins of the socket.
4. The phase of PIN1-3 and PIN7-9 is adjustable, and the user can configure the phase of the two pairs of outputs through one switch.

Flexible I2S and Clock Configuration:
1. Switch 1-4 corresponds to the PIN13-16 pin of the HDMI socket. When it is pulled to the ON position, it means that the PIN pin has the output function of the DSD_ON signal;

2. Switches 5 and 6 are modes for configuring the clock output:

    When the switch 5 is at O, the clock outputs MCLK, and when it is ON, the clock outputs WCK;

    Switch 6 configures the frequency of MCLK, which is 22.5792M/24.576M for O and 45.1584M/49.152M for ON.

    The configuration of switch 6 is valid for CLK OUT, RJ45-I2S, and HDMI-I2S.

3. The switch 7 can separately set the left and right channels in the DSD mode of the I2S signal.

4. Switch 8 can set the line sequence of BCLK in I2S signal; when O, PIN4 is BCLK+, PIN6 is BCLK-;

5. Switch 9 can set the line sequence of LRCLK in I2S signal; when O, PIN7 is LRCLK+, PIN9 is LRCLK-;

6. Switch 10 can set the line sequence of DATA in I2S signal; when O, PIN1 is DATA+, PIN3 is DATA-;

Note:
- Coaxial, optical fiber, AES/EBU output is not affected by the above code switch; RJ45-I2S wire sequence is fixed, need to adapt to different interfaces, you need to customize the network cable.
- Optional Version: SU-6 Black US Version, SU-6 Black EU Version. Please tell us the version you want when purchasing. Thank you!

Package Included:
- 1 x Singxer SU-6 USB Digital Audio Interface
- 1 x USB Cable
- 1 x Universal Power Adapter (Support AC100V-240V)
- 1 x Power Cable