AS-1 (Version 2021):

(Dual ES9028Pro + 1 FPGA Processor)

Ultra Low Distortion Fully Balanced DAC

Dual Sabre ES9028Pro

Built-in FPGA processor, no Jitter

32bit / 384K asynchronous transmission Amanero USB interface applies FPGA synchronous clock

USB / HDMI support to DSD512

Use of OCC, Hi-end grade accessories.

Power requirement:

Version 1: 100-130V  AC 50/60 Hz
Version 2:  220-240V  AC 50/60 Hz

Features of the AS-1 (Model 2021):

1, The USB transmits both the IIS signal to the FPGA processor and also receives the synchronous clock signal from the FPGA processor. The USB interface itself is no longer equipped with a data clock, using the synchronous clock makes the signal transmission more accurate, resulting in a significant increase in sound quality close to that of the previous AS-1 plus DI-20 (but not DI-20HE).

2. The ESS9028PRO/9038PRO uses the same clock as the FPGA.

ESS9028 Pro specs:

Who needs the AS-1:

The AS-1 is not the world's lowest distortion DAC, but it has ultra-low distortion at a fraction of the price.

Every AS-1 purchased comes with a distortion test chart (it is normal for the THD test chart to vary by a few DBs, the first 20 units are supplied with the AP SYS2722 test chart and the subsequent AP ATS-2 test chart, the ATS-2 test chart will be approximately 6 DBs worse than the SYS-2722, but this does not mean that the actual performance of the machine is 6 DBs worse). We welcome customers to use professional equipment to verify the performance.

We understand that a reasonable second harmonic can make a sound sound friendly and listenable, while a reasonable third harmonic can make a sound vivid and transparent. Matching the amount of distortion between the second and third harmonics is a secret design trick. This is why some equipment with high THD, such as vinyl disc systems, and a few expensive European brands of audio equipment, sound more musical than some equipment with lower THD.

In the AS-1, we did not technically adjust the THD value to tweak the sound, but simply kept the distortion very low by choosing different devices to make the sound more pleasant. Please note that this is not a traditional Rexroth style of sound.

Who would need the AS-1?

1, People who are most concerned about metrics.

2. People who need a very monitored sound to test cables, rooms, speakers or to test some accessories in the sound.

Some specifications of the AS-1 (Measured by AP SYS-2722, product aged for 300 hours):

THD . (Even if the same machine is measured at the same minute, there may be a difference of several DB in the measured value, so I have put several charts below at different times for reference. If the mains power supply used for the test is not treated, the results may vary in some bands at different times.) :

Distortion to Frequency (this distortion graph is less affected by different test times):

Frequency response (this graph is less affected by different test times)

Jitter test with 12KHz clock as standard (clock ageing time and mains purity have a number of DB effects)

Instructions for use:

HDMI definitions : (PS audio format compatible)

The MLCK signal is not required for this unit, but will not be affected even if the signal source has an MLCK output.

Setting button:

This button is used to set the digital filter parameters of the PCM and DSD and whether the display is automatically switched off.

Press the Setting button and the display on the left flashes for a few seconds. While it is flashing, press the Select button to change the display from 1 to 7. The internal PCM filter operating state is set with the corresponding number.

Press the Setting key again and the middle display will flash for a few seconds. While it is flashing, press Select to change the display from 4 to 7. The internal DSD filter operating state will then be set with the corresponding digit.

Pressing the Setting key again causes the left and centre displays to flash, then pressing Select right changes the display between "ON" and "OF". "OF" means that the display will automatically switch off approximately 10 seconds after the key operation has stopped. "ON" means that the monitor will not turn off automatically after power is applied.

If the display is not flashing, the Select key is used to select the input signal source. The selected input channel number is shown on the display to the right.