SDA-6 is a high-performance DAC developed by our Singxer team. It uses XMOS’ latest xCORE-200 series chip XU208 as the USB Audio solution, and uses AKM’s third-generation flagship DAC: AK4499 as the main chip for digital-to-analog conversion, AK4118 As a digital audio input receiving chip, STM32 is used as the control core of the whole machine, and Xilinx's large-scale FPGA is used as a clock system and digital audio stream processing. PCM supports up to 384Khz, DSD adopts native direct solution technology, and supports up to DSD512.
The DAC chip adopts the latest AK4499 released by AKM in 2019; DSD adopts the native direct solution mode, and the DSD digital stream does not pass through the internal digital filter and works in the NOS mode, which fully conforms to the design concept of HQPlayer.
It has a wealth of input and output interfaces, including standard USB2.0 input interface, SPDIF and BNC coaxial and AES balanced input, HDMI-I2S input interface, analog output including XLR balanced output and RCA single-ended output; all interfaces support DSD input.
SDA-6 supports external clock input, among which USB supports 10M clock input, and other interfaces support WCK input. In USB mode, it also supports a switchable input impedance of 50 and 75 ohms
- Self-developed adaptive clock system technology, built-in 4 independent ultra-low jitter audio crystal oscillators, equipped with a femtosecond-level local clock system for the USB part, the standard version of the crystal oscillator is AS-318B, and the high version is CCHD- 957.
- High-performance digital-analog hybrid phase-locked loop, excellent clock synchronization recovery technology, can greatly filter the secondary PLL of the external digital input jitter;
- It adopts 4 channels of fully balanced and full DC discrete circuit output; among them, the high-profile version adopts non-loop negative feedback output;
- Large-scale FPGA for digital audio signal processing, self-developed second-generation algorithm, original multi-input channel isolation technology, to ensure the purity of each input signal.
- Built-in 40 watt custom O-type transformer, output 4 independent power supply windings, up to 20 groups of distributed voltage stabilized circuits; among them, the reference power supply provided for AK4499 is the newly developed chao low noise (as low as 0.5uV RMS) power supply system.
Supported audio format:
- Sampling rate supported by each input interface:
- PCM: 44.1KHz, 48KHz, 88.2KHz, 96KHz,
- 176.4KHz, 192KHz, 352.8KHz, 384KHz
- [USB and I2S support all sampling rates, S/PDIF supports up to 192KHz]
- DSD: 2.8 MHz (DSD64)-DoP, native
- 5.6 MHz (DSD128)-DoP,native
- 11.2 MHz (DSD256)-DoP,native
- 22.5792 MHz (DSD512)-native
- [USB and I2S support all DSD formats, S/PDIF and AES/EBU support DSD64 DOP mode]
- Bit width: up to 32 bit over USB and I2S
- Up to 24 bit over S/PDIF
Electrical standards for each digital interface:
- The USB input socket is a standard USB-B type female socket, and the USB power supply range is 4.5V-5.1V;
- The SPDIF interface inputs standard S/PDIF signals, the input impedance is 75 ohms, and the AES input impedance is 110 ohms;
- The power input is 115V/230V AC, and a 40-watt customized transformer is used for power supply;
- I2S input is LVDS level in the form of HDMI interface, compatible with most front-end equipment;
Analog audio output performance:
- Output level (0dBFS):
- PCM: RCA single-ended output is 2.25V RMS, XLR balanced output is 4.5V RMS
- DSD: RCA single-ended output is 1.8V RMS, XLR balanced output is 3.6V RMS
- Output impedance: 22 ohms (RCA single-ended) / 45 ohms (XLR balanced)
- Frequency response: 20-20kHz +/-0.1dB
- Signal to noise ratio: 131dB (20-22kHz A weighting)
- Distortion characteristics:
- THD+N (1kHz, 0dBFS) 0.00012% (-118db) at fs=44.1Khz (PCM, 20Hz-22kHz A weighting))
- Dynamic response (1kHz, -60dBFS) 131dB (20Hz-22kHz A weighting)
- Left and right channel separation >130dB @1kHz