SINGXER SDA-6 PRO 2 Dual AK4499EX Decoder

PRO2 new version of the main improvement part:

1. Using AKM fourth generation flagship DAC: AK4191 + two AK4499EX as the main chip for digital-to-analog conversion;

2. USB part of the crystal using femtosecond clock with our self-developed thermostatic tank, to achieve the clock system in a constant temperature environment;

3. XMOS upgraded to the new XU316 chip as the USB Audio program, the highest support DSD512, PCM 768K sample rate.

4. Upgraded with specially optimized ultra-low noise power supply system, completely solved the problem of large low-frequency distortion of AKM DAC;

5. With digital preamp, support volume adjustment, analog high and low gain adjustment, OLED brightness adjustment and off-screen playback;

SDA-6 is a high-performance DAC developed by our Singxer team, which uses AKM's fourth-generation flagship DAC: AK4191 + two AK4499EX as the main chip for digital-to-analog conversion; AK4118 as the digital audio input and receiver chip, using STM32 as the control core of the whole machine, Xilinx's large-scale FPGA as the clock system and the The PCM supports up to 768Khz, and the DSD supports native direct decoding up to DSD512.

The DAC chip adopts two AK4499EX released by AKM in 2022; DSD can be selected as the native direct mode, and the DSD digital stream does not go through the internal digital filter, and works in NOS mode, which is fully in line with the design idea of HQPlayer.

With rich input and output interfaces, including standard USB2.0 input interface, SPDIF with BNC coaxial and AES balanced input, HDMI-I2S input interface, analog output including XLR balanced output and RCA single-ended output; full interface support DSD input.

The SDA-6 PRO supports external clock inputs, of which USB supports 10M clock input and other interfaces support WCK input. In USB mode, it also supports 50 and 75 ohm switchable input impedance.

Main technical features:

1. self-developed adaptive clock system technology, built-in 4-way independent ultra-low jitter audio crystal, configure femtosecond local clock system for USB part, with our self-developed thermostat technology to achieve constant temperature crystal.

2. High-performance digital-analog hybrid phase-locked loop, excellent clock synchronization recovery technology, can significantly filter external digital input jitter secondary PLL;

3. 4-way fully balanced full DC Class A discrete circuit output;

4. large FPGA for digital audio signal processing, self-developed third-generation algorithms, original multi-input channel isolation technology to ensure the purity of each input signal.

5. Built-in 40-watt customized O-type transformer, the output of four independent power supply winding, up to 20 groups of distributed voltage regulator line; which provides the reference power supply for the AK4499EX is a newly developed chao low noise (down to 0.3uV RMS) power supply system.

All versions support switching between 115V and 230V AC voltage with internal toggle switch.

Here is the test data for the production version of the SDA-6 PRO, based on the APX555: