Since 15th May, the Master 7 Singularity had update the firmware to include the NOS 7 firmware in one unit.

Users can select the unit working as NOS 7 model or original  Master 7 Singularity model  .
　

Master 7 (Singularity)

(The PCM1704UK stock in an emergency,
Global 100 units limit)
Dedicated Discrete Fully Balanced DAC
User setting between NOS,2x,4x and 8x Oversampling
Built in 8 PCs top grade R-2R  PCM1704UK
32bit / 384K Amanero combo384 with USB isolator
Supports up to 384KHz /32Bit at USB & IIS
Supports up to 192KHz /24Bit at SPDIF
OCC wires & TCXOs applied
Building with top grade parts & workmanship

Price:      (Exclude shipping cost)
USD2480 (Without USB Isolator)
USD2512 (With USB Isolator)
HDMI and AES/EBU can be custom order.

Audio-gd products had design and test based on the AP SYS-2722 (The top-drawer professional equipment in world) 


USB specs and driver install guide :   Amanero combo 384
USB isolator upgrade for Amanero combo 384 as default configure since 11st. Dec.
   
USB isolator can avoid the computer electric interrupt feed in the DAC cause the sound quality worse .  In AB compare , it can improve on sound transparency slightly .
After USB isolator upgrade, the USB spend the USB power supply, and can not support phones because the power limit of the phones .

Singularity 7，the total full new design:
           Most DAC products design , will applied the normal Logic chips to process the digital signal, but the normal Logic chips most had the 40HMz speed. In long term ago, the music files only had 44.1K and 48K,40MHz is enough for process the signal. But nowdays, 384K music files had popular, 40MHz limit even can play the sound but the input signal speed had close the chips highest working frequency, the signal had serious delay and distortion, cause the sound lost a lot detail .
          Now, Singularity 7 release, the design had give up the normal and low performance chips, which is only can working with tens MHz frequency clock , it applied two pcs Xilinx CPLD, and an Altera FPGA to perform all the data process . All three chips can process a lot different data simultaneity up to 450MHz speed, and simultaneity data process can much exact to process and this is most important in digital audio area .
           Singularity 7, built in two high performance TCXOs for process different sampling signal, working as in the no jitter state, revert all detail and soul of the musics .
           Singularity 7, no longer had the performance and sound quality limit by the normal and fixed function chips like the DIR9001, WM8805 and the DF1706, all function blocks are through the design with the ultra speed characteristic in the FPGA, can got the best timing performance ,  minimal jitter , boost the sound quality most neutral , the detail, dynamic can fully show in your system.
           Singularity 7, through FPGA design and perform below hardware circuits:
           SPDIF (coaxial and optical ) decoder .
           AES/ EBU decoder.
          Source signal select with minimal timing delay .
          Clock signal regeneration .
          Digital signal process and refuse jitter process.
          Digital filter process.
          Singularity 7，I had design the most neutral sound quality, but for best suite the users personal flavors which is like the coloration sound flavor , it had built in different setting for users can through change the setting and oversampling (8x, 4x, 2x and NOS) to get different sound flavors .
          Singularity 7, applied the top grade R-2R  PCM1704UK chips ,which is famous in world, even through I had order a large number from TI before the PCM1704 discontinued , but for the hot sale in these years, the stock in an emergency , I only can arrange to build 100 units Singularity 7 , not long later, the product which is built in PCM1704 will become story .
          Singularity 7 , the sampling support of all inputs as below (Cause by the PCM1704 support up to 1536KHz sampling, so the 192KHz or lower sampling can working between NOS to 8x times oversampling, over 192KHz will working with 4x times oversampling auto, or by the users setting between NOS to 4x times oversampling ).
           IN1 ： BNC coaxial input, support up to 24bit / 192KHz .
           IN2 ： RCA coaxial input, support up to 24bit / 192KHz .
           IN3 ： RCA coaxial input, support up to 24bit / 192KHz .
           IN4 ： Optical  input, support up to 24bit / 192KHz .(note 1)
           IN5 ： IIS input, support up to 32bit / 384KHz .(note 2)
           IN6 ： USB input, support up to 32bit / 384KHz .
          Singularity 7, except the full new digital design, but the analog design had improve for get lower distortion and better transparency sound quality .
(Note: 1, The optical receiver had applied the 25M bandwide parts, it can support up to 24bit / 192KHz in test, but the worldwide standard is up to 96KHz , so users must check your source if support up to 192K.
           2, The IIS input can support up to 384KHz in test but if the transmit cable is too long or had worst quality, it may can't achieve the design performance .)

Singularity 7 technology detail:

ACSS ： 
              Singularity 7, is a real fully balanced discrete design.
              Applies the 8 Pieces Expensive high-end grade PCM1704UK, which is the top grade R-2R chips, every channel had built in 4 pcs , every 2 pcs in parallel, and then they are working in balance mode . In my particular design, all 8 pcs PCM1704 are working for outputs, even just connect the RCA outputs .
              
               The SPDIF inputs can support up to 24Bit / 192KHz ,and the USB, IIS inputs support up to 32Bit / 384KHz .Cause by the PCM1704 support up to 1536KHz sampling, so the 192KHz or lower sampling can working between NOS to 8x times oversampling, over 192KHz will working with 4x times oversampling auto, or by the users setting between NOS to 4x times oversampling .
               Different to other PCM1704UK designs , it applied Non-feedback ACSS analog stages. The 8 pcs PCM1704UK feed to the ACSS analog stages without any OPAs and couple caps so it can avoid sound coloration .
              The ACSS is a non-feedback technology made with fully discrete amplifiers. Most people know the global feedback design can offer better specs in test measurements, and classic non-feedback can't do well in test measurements but can offer better sound for the human's ears. Here is a conflict of the classic circuits. But the ACSS opens a new field, it can offer a least coloration sound which is more neutral with very low distortion and high linearity. So it can retain the dynamics, detail and neutral sound but not sound bright or harsh.
              About the ACSS technology detail, Mr. Ho had post some few articles in the monthly <Radio & television > since 2007 year.  

Output buffers :       
    The output buffers are newest improve version Non-feedback   pure class A FET Cascode desgn  . Its distortion is much lower than the last version . For low impedance, it applied the dual FET buffer output stage which is quite less colored than most conventional circuits, the output impedance is less than 10 ohm.

Processor:
           Most DAC products design , will applied the normal Logic chips to process the digital signal, but the normal Logic chips most had the 40HMz speed. In long term ago, the music files only had 44.1K and 48K,40MHz is enough for process the signal. But nowdays, 384K music files had popular, 40MHz limit even can play the sound but the input signal speed had close the chips highest working frequency, the signal had serious delay and distortion, cause the sound lost a lot detail .
          Now, Singularity 7 release, the design had give up the normal and low performance chips, which is only can working with tens MHz frequency clock , it applied two pcs Xilinx CPLD, and an Altera FPGA to perform all the data process . All three chips can process a lot different data simultaneity up to 450MHz speed, and simultaneity data process can much exact to process and this is most important in digital audio area .
           Singularity 7, built in two high performance TCXOs for process different sampling signal, working as in the no jitter state, revert all detail and soul of the musics .
           Singularity 7, no longer had the performance and sound quality limit by the normal and fixed function chips like the DIR9001, WM8805 and the DF1706, all function blocks are through the design with the ultra speed characteristic in the FPGA, can got the best timing performance ,  minimal jitter , boost the sound quality most neutral , the detail, dynamic can fully show in your system.
           Singularity 7, through FPGA design and perform below hardware circuits:
           SPDIF (coaxial and optical ) decoder .
           AES/ EBU decoder.
          Source signal select with minimal timing delay .
          Clock signal regeneration .
          Digital signal process and refuse jitter process.
          Digital filter process.
          Singularity 7，I had design the most neutral sound quality, but for best suite the users personal flavors which is like the coloration sound flavor , it had built in different setting for users can through change the setting and oversampling (8x, 4x, 2x and NOS) to get different sound flavors .
          

Power supply:
            Singularity 7 applies the excellent 8 pcs PCM1704UK and excellent analog output stages, but these are not the only keys of the best sound.
            The power supply is most important. Anythings in the signal are source from the power supply .
            Even applying the best DA chip and the best amp, if matched to a normal power supply, the total sound may still be average or sound musical, but can't be neutral and detailed.
             Singularity 7 had total 3 units R core transformer for power supply the digital and analog separate. And more than 50,000 UF caps for smooth the power supply .There are  total 22 PSU groups are applied. Uses 19 groups of high-quality class A parallel connection PSU with dedicated DC supply double-stage PSU.
              The class A parallel connection PSU had ultra high input impedance, which is can refuse the  power interrupt through the PSU , it also had very low output impedance ,which can offer very clear DC power for the DAC, producing a very black background and neutral sound characteristic. The double-stage PSU is very important for digital parts. Some designs may have very low jitter in theory, but if the power is supplied by a dirty or low-speed power supply, it will increase the jitter and pollute the data, and degrade the sound quality obviously.
            Why to said how excellent of the class A parallel connect PSU but less design in the audio products? This just same as the pure class A amp, it had high request on the parts quality and building workmanship , in nowdays the money world , even the expensive brands had not like to applied.
                

Building:
          Singularity 7, it is not put the parts full in the chassis, but the audio grade parts can offer better performance and working steady . Applied the normal parts not worst if the design is excellent, still can had rich musical , but no way to had the most neutral sound .
            Singularity 7 had most applied DALE, WIMA and Nover ect. audio grade parts, and the Canare , Natrik sockets, and the OCC wires, custom order TCXOs which is building without compromise .
            Singularity 7, assemble in a heavy monsters chassis which is built by pure aluminium . It had the thick aluminium board to separate the power transformer, digital parts , the left and right analog parts. Even the IEC power inlet, had shield in a pure cooper shield box .
           
            Singularity 7 , every unit finished the parts assemble , must had the full test by the technician , then build by another technician . There are 300 hours burn in time after building, during the burn in time, every unit must had two times test in every day . Finally , the QC technician had the final test and audition before package and shipping.  The complex process in the building , just for keep every units had the highest quality .