The different between dual ES9038 Pro and single ES9038 Pro is large:
                The different not only the DNR, but the dual ES9038 Pro working under mono mode, the channel crossing is improved for offer a larger and exact sound stage.

 
            Even the ESS9028 Pro, working under mono mode, its DNR had 3DB better than one ES9038 Pro .


The FPGA is important in the D-77:
           1, Separate the data feed to dual ES9038 Pro for working in mono mode.
           2, Clock re-clock process and FIFO design for all inputs , the output data can exact synchronisation with clock signal, reject jitter.
           3, Built in high performance SPDIF interface , bypassing  low performance SPDIF interface of the ES9038 Pro .
What is  the FPGA duty  in the D-77:
           1, Separate the data feed to dual ES9038 Pro for working in mono mode.
           2, Clock re-clock process and FIFO design for all inputs , the output data can exact synchronisation with clock signal, reject jitter.
           3, Built in high performance SPDIF interface , bypassing  low performance SPDIF interface of the ES9038 Pro .

Full discrete output stages:
           The signal last stage is  the analog output stags , they greatly  effect the whole DAC sound quality.
           The output stages working after ES9038 pro, they are full discrete transistor built with hole parts but not SMD parts .
           The high speed ACSS amps work as the signal gain and processing , they are of non feedback design and working in  current signal mode  . the dual ES9038 pro output [current signal] goes through the ACSS amp .
           In our design  output stages  working in pure class A , and without any negative feedback for the most pure and life like  sound reproduction .
           There are 4 pcs OPA built in as DC servo , so the DAC can be  working well without coupling caps  and output the most neutral sound.


Heavy power supplies design:
           There are in total 16 groups PSUs . 
           A total 13 groups of ultra speed linear PSUs  (dual stages PSU to  remove the power interruptions ). PSUs deliver cleanest power  to allow  digital circuits working under best conditions .
           2 groups of pure class A PSUs to  power  to the analog circuits and deliver most  analog sound .
           The control and display circuits are powered by a separate PSU  to  avoid adding any additional noise to the rest of the circuit.
　

S/N Ratio	>120DB  (XLR output)
THD	<0.0003%
Output impedance	4.7 ohm
Output Level	2.5V (RCA) 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	30W
Package Weight	Approximately 5.5KG
Dimensions	W240 X L360 X H80 (MM, Fully aluminium )
Accessories	AC power cord            X1 USB cable                X1