Price:   USD788 ( Exclude shipping cost)
Two chassis versions available, customer must inform while place the order ,otherwise we ship the edition randomly:
R-1 MK3 Black
R-1 MK3 Silver
Please send your address, name  to audio-gd@vip.163.com  get the quote.

Click to download the driver of  Amanero combo 384

R-1 MK3 feature:
1,     Built in isolator for total isolate of the all inputs include USB,HDMI and spdif inputs , and the FPGA processor to the  analog parts  .
2,     Fully balance discrete transistors analog part design.
3,    R core transformer power supply separately, built in 7 ground ultra speed linear PSUs and two ground pure class A PSUs
5,     Real balance DAC design ,built in 4 group fully discrete real balanced DSD native decoders , 8 group fully discrete R-2R PCM decoders and 32bit / PCM384K /DSD512 asynchronous transfer Amanero 384 .
6,     USB  transmit the IIS signal to the FPGA processor and receive the clock signal from the FPGA processor, the USB interface without on board data clocks, the signal transmit is much exact, the sound quality get the much improve .
7,      The FPGA process data in the  parallel mode.
         The IIS data is series transmit mode, every data must need one clock cycle to process or transmit, one frame data ( Include L and R data) must need 64 clock cycle to process or transmit, so the data has effect by the 64 clock cycles.
         But the parallel data process and transmit mode only need one clock cycle can finish the one frame data process and transmit, that can avoid the effect of clock stability .
          The IIS input (Include USB and HDMI-IIS) has recombine become dual 32bit parallel data once input , and the SPDIF input after decoder, has recombine become dual 24bit parallel data, and the DSD input has recombine become dual 64bit parallel data once input.
          The parallel process and transmit mode can improve the sound quality on the transparency and detail but still analog.
8,       Full new configuration clock manage design built in, improved on the clock timing.
9,      DSD asynchronous clock technology has apply that improves the sound quality obviously.
10,      DOP support from SPDIF input .

The advantages and disadvantages of R-2R DAC:
Advantages:
         1, R-2R will not convert the clock signal to the output signal.
         2, R-2R is not sensitive to jitter but Delta-Sigma is quite sensitive.
         3, The output signal level of R-2R is more accurate than Delta-Sigma.
Disadvantages:
         1, R2R's harmonic distortion can be quite low but not as low as the ES9038 PRO (Delta-Sigma) harmonic distortion.
         2, The accuracy and inherent glitches of resistor ladders are not easy to deal with.

R-2R design popular in the market:
         Whether it is DIY kits or factory products, R-2R has become popular.
         In the low-cost DIY kit market, the usual design is based on the old MSB technology, but only retain the signal conversion part and discard the exquisite design of the original product.  
        This design uses data serial input to a shift register IC to convert data to an analog signal. It is not able to solve the technical problem of R-2R at all. The performance of this design is completely dependent on the accuracy of the ladder resistances.

          The factory products in the high-end market use quite complex technology to solve the problems of R-2R, in order to achieve high performance and sound quality. Some manufacturers use the serial control mode of the shift register IC.
          The design in the figure below uses an FPGA to control the step resistance switching in parallel. With the parallel control mode, the step resistance switch of each bit is individually controlled, so it has ultra-high speed (parallel mode only needs 1 clock cycle to output all bits, serial mode requires at least 8 to 24 clock cycles) to send or update the data, and can correct the data at any time to achieve an output signal with low-distortion characteristics, and solve the problems caused by resistance tolerances and switching glitches.

       

The accuracy of the step resistance:
        Many people only care about the accuracy of the step resistances because they think that R-2R depends essentially on the accuracy of the resistance.
        Nowadays, 24 bit is a standard, but can the precision of manufactured resistors reach 24 bit? Even with only 16 bits, the accuracy requirement is 1/66536, and so 0.1% (1/1000) of accuracy is completely inadequate. In fact, 0.01% (1/10000) would still fail to meet the 16-bit requirement, let alone 24 bits.
         Therefore, lowering accuracy of the resistance is not enough to solve the problem. If there were 0.00001% resistors available on the market, it would meet the requirement of 24 bits, but the inherent resistance of the switching devices would completely wipe out this super high accuracy advantage.
          We need to solve the problem technically, not just improve the accuracy of the resistance. But we still use ultra-high precision resistors in our products.
           

Importunacy of the FPGA/CPLD:
          On important thing to underline about the FPGA/CPLDs is that they are programmable logic array devices. Nowadays, FPGAs have been used in many high-end DAC products, such as the popular ROCKNA WAVEDREAM DAC.
          Since 2008, we have used FPGA designs in DAC products. This machine is composed of one FPGA and 5 CPLDs at the heart of digital processing.
          The hardware layout inside the FPGA can be designed and arranged through software, therefore the hardware can be upgraded through software updates.
           As a benefit, this design has a high degree of flexibility. It allows improving sound quality, adding functions, and keeping the product up-to-date, all through software (firmware) updates.
　

Responsibilities hor the FPGA/CPLDs:
         1. the FPGA implements a high-performance SPDIF demodulator (instead of using low-performance SPDIF demodulator chips such as DIR9001, WM8805, AK411X, etc...).
         2. Combining clocking and FIFO technology to output data, it can be accurately synchronized to the clock, and thus reject jitter.
         3. Built-in 2X, 4X and 8X digital filters and different NOS modes allow users to choose the tone that best suits their personal taste.
         4. Simulate the tonality of vinyl disc playback through a unique design.

Fully discrete output stage:
          The last stage in the signal journey is the analog output stage, and the output stage has a decisive influence on the sound quality of the DAC.
          No matter how excellent digital circuit design is, without an excellent analog output stage design, the sound quality will become extremely ordinary.
          The analog output stage is directly connected behind the DA 7 module, using only through-hole components (not SMD).
          The high-speed ACSS amplifier is used for signal amplification and processing. The ACSS amplifier is designed without negative feedback and works in the current signal mode. It does not have to repeatedly transform the signal between current and voltage like other designs.
          The output buffer stage is a single-ended pure class-A FET design, and the two groups are connected in parallel to achieve a lower output impedance. All in all, the output stage is working in a pure class-A state, with no negative feedback at all, so that it can reproduce pure and lifelike sound signals.
           The DAC has four built-in operational amplifiers to serve in the DC servo function, so that the DAC can work without coupling capacitors, avoiding noise and coloration. In the whole signal channels following the DA module, no switching elements are used to achieve the truest and purest sound quality.