S/N Ratio
>120DB  (XLR output)


Output impedance
10 ohm

Output Level
2.25V (RCA)
4.5V (XLR)
2+2MA (ACSS)
Input Sensitivity
0.5 Vp-p(75 Ohms, Coaxial)
19 dBm (Optical) 
Frequency Response
20Hz - 20KHz (< - 0.1DB)

Support Operate Systems (USB)

Windows , OSX ,Linux, ISO

Support Sampling  
PCM of USB and I2S: 44.1kHz-84kHz
DSD of USB and I2S: DSD64-512
 Coaxial model: 44.1kHz-192kHz 
Optical model: 44.1kHz-96kHz 
Power Requirement
 Version 1: 100-130V  AC 50/60 Hz
Version 2:  220-240V  AC 50/60 Hz
Power Consumption
Package Weight
Approximately 5.5KG

W240 X L360 X H80 (MM, Fully aluminium ) 
AC power cord            X1
USB cable                X1

Đang cập nhật

Why it built in ES9028 pro ?
        We applied ESS9028Pro but not ESS9038Pro because the ESS9028Pro much cheaper and already can offer the very low distortion.
        We accept custom order ESS9038 Pro version, leadtime is 15 days, price USD963 with 3 pc TCXOs build in. 

ESS9028 Pro specs:

Who need the AS-1:

           AS-1 is not the lowest distortion DAC in world, but it had the ultra low distortion and price is not expensive. 
          AS-1 is not only declare with the words has low distortion,  we offer the measure diagram for every single unit (It is normal that the THD has few DB different, the first 20 units offer AP SYS-2722 measure diagram, after that will offer AP ATS-2 measure diagram, ATS-2 measure diagram will has around 6DB worst than SYS-2722, but it is not mean the unit performance worse),  verify by the professional instruments is welcome. 
           We known that the proper 2nd THD makes the sound become smooth and rich,  the proper 3rd THD makes the sound become transparency and lively, how to adjust the level of 2nd and 3rd THD is the secret technology of the designers, that is why some audio devices have the higher distortion like phono, and some few very expensive European made audio devices  had better musical to most people than some others low distortion devices .
           We had not applied technology method to adjust the AS-1 THD effect the sound flavor, we just made it has the very low distortion , and through selected the different parts apply to keep the sound listening pleasant . It is not the audio-gd house sound style.
           Who need the AS-1?
           I guess that is in below:
           1, Who concern the specs at first .
           2, Who want a monitor sound to test the cable, room, speakers  or somethings of audio.

Some specs of the AS-1 (Measured by AP SYS-2722,unit with 300 hrs burn in):
           THD . (the same unit measure in same minute , the peak level result may has few DB different, so I test the same unit in different time and post the result in below) :


Distortion to Frequency (This diagram effect has less effect by the different test time):

Frequency band  (This diagram effect has less effect by the different test time):

Jitter test with 12KHz with the stock clocks. (The clock burn in time and power supply clean can have few DB effect )