Di-20 Digital Interface

Built-in Amanero interface using isolator separation, PCM384K / DSD512

FPGA coaxial receiver interface supports up to PCM384K and DOP

Current transfer and conventional coaxial output support up to 384K

R-cow and 13 groups of high speed linear regulated power supplies,

FPGA-based design offers unlimited possibilities for upgrading the sound quality, so that the internal hardware can be updated in the future simply by connecting to a PC.

Please note:

The DI-20 has a built-in super speed isolator, the USB should be connected directly to the computer USB port, please do not connect an external USB isolator to avoid possible improper operation.

Due to the many different IIS standard definitions, we only guarantee compatibility with our DACs, not with other brands.

Please note:

This product has a built-in Amanero interface and is compatible with WINs, Apple OS and IOS and PC-based Linux/Android (including Raspberry, newer Android phones and TVs). However, good compatibility with USB outputs for digital turntables is not guaranteed.

Accusilicon clocks used in the motherboard:

The main difference between the Accusilicon 45/49M version and the 90/98M version is the different clock frequencies used (the 90/98M clocks are twice as expensive as the 45/49M). The main difference is that the 45/49M version will require the creation of a PLL to boost the frequency when the sampling rate requires clocks above 45/49M, whereas the 90/98M does not require a PLL.

The TCXO and 45/49M versions are socket-mounted for easy replacement in the future. 90/98M version clocks are soldered directly to the circuit board.

Please note that:

This machine does not include a USB cable and power cable, users need to bring their own good quality USB cable and power cable. If you need a Greenlink USB cable, please let us know when you place your order ($20).

Design and production characteristics.

1, using the very good compatibility and stability of the Amanero USB interface, in the test process any switch tracks from no dead phenomenon. Supports WIN, OSX, IOS (iPhone, iPad), LINUX and some Android TVs (Android phones have not been tested).

2, Has a 10MHz clock input interface for connection to an external clock generator.

3, Master clock / WCK clock output interface, clock output type can be set by the user.

4, USB and coaxial input (DOP support) can be passed to HDMI-IIS and coaxial output (DOP output is not supported yet), coaxial input and output is designed by FPGA and the very common coaxial input and output circuit built by USB chip, with higher processing speed and better sound quality, coaxial input and output supports 384K sample rate.

5, HDMI-IIS output can be set through the display menu PCM and DSD output format.

6, Using the best sound quality R-type transformer and 13 groups of voltage regulator to form a dual voltage regulator power supply for each different signal properties circuit separate power supply.

7. The USB interface is isolated from the FPGA signal processing circuitry to prevent interference from the computer affecting the FPGA signal processing circuitry. As the isolator affects the transmission of signals and clocks from the USB to the FPGA, the signals and clocks are recalibrated at the FPGA.

8, the USB interface uses the same clock as the FPGA signal processing circuitry to avoid any clock desynchronisation or deviations affecting the sound quality. The new architecture of the clock management design allows for more stable clock operation and greater transparency and detail.

9, FPGA data processing mode can be set by the user in parallel or serial processing mode.

The USB output IIS signal is serial data mode, each data requires one clock cycle, one frame of left and right channel data requires 64 clock cycles, subject to the stability of 64 clock cycles.

The parallel mode requires only one clock to transmit and process the 32-bit data of the left and right channels, which greatly increases the operating speed and is more independent of the clock stability.

The USB input data and the demodulated SPDIF signal are immediately reassembled into two sets of 32-bit parallel data and sent to the next level of processing, while the DSD data is also reassembled into two sets of 64-bit parallel data as soon as it is input.

In parallel processing mode, all data runs at 256 times the clock frequency, which is uncommon for 64-256 times the clock frequency depending on the sample rate. The fixed and higher clocks allow for more precise timing alignment of the signals, resulting in a uniform standard of data processing and consistent music sound across different sample rates.

10, Multi-function display for PCM and DSD playback sample rates and a human-machine interface for user set-up of internal functions.

11, with USB firmware upgrade button and FPGA firmware upgrade interface, upgrade the firmware without opening the machine, providing unlimited upgrades in the future.

12, Data and clock are more likely to be affected and interfered with in the transmission than analogue signals, resulting in the DAC decoding sound quality deterioration or even failure to work properly, the machine uses multiple independent powerful driver chips to output various data and clock signals to ensure that it is more difficult to be interfered with in the transmission process.

13, exclusive second generation CAST current transmission coaxial output design, through the current signal output coaxial signal, reduce by the quality of the wire and transmission of interference. Even ordinary DACs can be connected to this interface and benefit from the advantages of current transmission. It also has a transmission transformer coaxial output circuit for better compatibility with various DACs.

Suggestions for use:

1, the machine has been aged for 100 hours before shipment, the user is advised to age it for an additional 300 hours. The clock is aged for 1000 hours.

2, The machine can be powered on for a long time without having to be switched off. (In thunderstorms it is recommended to switch off and switch off the connection cable to the computer and TV).

3, Please make sure to disconnect the unit from the DAC before plugging in the cable.

4, Please do not use overly thick USB and HDMI cables, and do not shake the cables to avoid damaging the sockets on the machine when plugging in all cables.

5, Please allow at least 30 seconds between each power up and the last power down.

6, The built-in power switch allows you to switch the working voltage of the machine if necessary (there is high voltage inside, do not open the case for non-professionals).

Front panel function description:

First left display:

Input channel indication. Display "1" to select USB input, display "2" to select coaxial input.

Second display from the left:

Use of internal/external clock indication. The display shows "I" (Inside) to use the internal clock and "E" (External) to use the external clock.

The other three displays:

Displays the sample rate of the current output signal. If playing a PCM signal 88.2K is displayed as "88.2". If playing DSD512, "512" is displayed.

Setting button:

Press to enter the function setting menu and the display will flash.

Ext Clk button.:

Press to select whether to use the internal or external clock. The external clock indicator light will only be lit when an external clock is connected and the external clock power and clock output are switched on. The selection can only be made when the external clock indicator is illuminated.

Please note:

If the external clock loses power or if the connection cable has a bad contact, even if the external clock is selected, it will automatically switch back to the internal clock and the "E" in the display will change to "I" to avoid noise.

Selector button.

Selects the input channel.

Rear panel functions described.

AES/EBU OUT :.

AES/EBU output (5VPP @ 110 Ohm).

S/PDIF OUT STD.

Conventional coaxial output with built-in silver wire isolation transformer (0.5VPP @ 75 Ohm).

S/PDIF OUT ACSS.

Current transmission CAST coaxial output. (0.5VPP @ 75 Ohm).

Using second generation current transmission technology, the current signal is transmitted coaxially to reduce the effect of the wire on the signal. the coaxial signal from the DI output is a current signal which is converted to a voltage coaxial signal of 0.5VPP by means of a 75 Ohm resistor at the DAC input, so that the DAC being connected can be used without special design and benefits from the current transmission technology. (If the DAC coaxial input uses a transformer input, or if the impedance is not 75 ohms, or if the input level does not comply with 0.5VPP @ 75Ohm, connecting this interface may not work properly.)

IIS OUT.

HDMI transmission IIS signal output (3.3V LVDS @ 110 Ohm). Only suitable for DACs with the same pin definition, please see below for different pin definitions, not compatible with conventional HDMI for audio/video transmission and not connectable.

CLK OUT.

Outputs 256fs master clock or LRCK/WCLK clock (3.3V LVDS @ 50 Ohm). User settable.

INPUT S/PDIF.

RCA 75 Ohm coaxial input (0.5VPP @ 75 Ohm).

INPUT 10MHz.

Input for connecting an external 10MHz clock (0.3VPP - 3VPP @ 50 Ohm).

INPUT USB.

USB input (USB2.0/USB3.0).

UPDATE PORT 10-pin socket.

Connects to the Altera Blaster downloader to upgrade the internal FPGA firmware via PC with a view to upgrading functionality or performance.

UPDATE PORT toggle switch.

Upgrade the internal Amanero firmware.

Setting function description:

Setting button.

Press to enter the setting menu, the first bit of the display will flash to indicate that the function represented by this bit can be changed by using the "Selector" button. Pressing the "Setting" button again while the display is flashing will shift the flashing bit one place to the right.

Ext Clk button.

Pressing the "Ext Clk" button while the menu function is being set moves the blinking bit one place to the left.

Selector button.

Press to change the blinker setting.

The first display bit.

"P" (Parallel) means that the internal signal processing is processed using 32-bit (PCM) or 64-bit (DSD) parallel mode. "S" (Series) means that the internal signal processing is handled in 1-bit serial mode. (USB input HDMI-IIS output supports parallel/serial mode, coaxial input/output only supports parallel mode.)

Second display bit.

"C" (Clock) means that the Clk OUT output signal that follows is a 256fs clock at the sample rate. "L" (LRCK/WCLK) represents the LRCK/WCLK clock for the output.

Third display bit.

"n" (Non Swap) represents that the HDMI output DSD left and right channels comply with the Audio-gd standard. "S" (Swap) means that the left and right channels of the DSD are swapped with the Audio-gd standard.

Fourth display bit.

"1" represents that the PCM pin definition of the HDMI output complies with the Audio-gd standard. "2" represents the other pin definition (see description below).

Fifth display bit.

"A" (Auto) represents that the display turns off automatically approximately 10 seconds after stopping operation of any button. "n" (Non Auto) means that the display will remain on.

HDMI-IIS output setting instructions:

HDMI output mode 1.

The third bit is set to "n" (Non swap), the fourth bit is set to "1": HDMI definition in line with Audio-gd or PS.

The third bit is set to "n" (Non swap) and the fourth bit is set to "2":

HDMI output mode 3.

The third bit is set to "S" (Swap) and the fourth bit is set to "1".

HDMI output mode 4.

The third bit is set to "S" (Swap) , the fourth bit is set to "2".