Please note: The PCM1704UK can not support DSD playback. User need
conversion the DSD to PCM in the source device.
( Exclude shipping cost .)
Please send your address, name to
get the quote.
Accusilicon 318B femtosecond clocks:
Click to download the
Master 7S (2021 version) feature:
1, USB and HDMI apply the separate isolators
and isolate pure class A PSUs for avoid the interrupt from computer
and HDMI sources. (New Feature)
2, USB apply the bidirectional isolator that
can 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 , similar to the last
generative Master 7 combine with DI-20 (But not DI-20HE) level.
3, HDMI input apply isolator for improve the
sound quality . (New Feature)
4, Input signal sampling display .(New Feature)
5, Support 10 MHz clock input.(New Feature)
6, 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
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.
7, Full new configuration clock
manage design built
in, improved on the clock timing.
Pros and cons of
PCM1704UK R-2R DAC :
1. R-2R will not convert the clock signal into the output
2. R-2R is not sensitive to jitter while Delta-Sigma D/A is
much more sensitive to jitter.
3. The output signal is much more precise compared to
Delta-Sigma D/A .
1.THD today is extremely good with Sigma Delta chips; R2R
ladders are good too but not as good.
2. Glitches and accuracy of the ladder resistors are very
difficult to avoid and require complex technology to resolve it.
Importunacy of the FPGA/CPLD:
stands for Programmable Array Logic.
Nowadays the FPGA is applied in a lot high end grade
DACs; like the popular ROCKNA WAVEDREAM DAC.
applied the FPGA in our DAC products since 2008.
Master 7S has built
in 1 pc FPGA and 3 pc CPLD programmable chipsets to separate the different
configured circuits for avoid interrupt.
The internal hardware design is fully controlled by
complex software. A huge advantage is the fact the software in the
FPGA can easily be upgraded offering new features or improve the
performance. Such design is much flexible and future proof!
FPGA/CPLD tasks :
1. The FPGA
high performance SPDIF interface, replacing
traditional SPDIF interface chips like DIR9001, WM8805 or AK411X wich
are lower in performance in comparison to FPGA.
2. Full re-clocking process with FIFO design applicable
on all inputs. This way the output data keeps fully synchronized
with the clock signal to reject any jitter.
3. Built in 2X, 4X and 8X oversampling and digital
filters and on top of this 4 different true NOS (only analog 6dB
filtering) modes. To completely configure it to your liking!
4. Built in the
especial design to simulate the TDA1541A + SAA7220 sound flavor.
.Fully discrete output stages
The signal last stage is the
analog output stages, which can greatly effect the whole DAC sound
After d/a conversion by the R2R D/A modules the analogue
signal is transported by fully discrete matched-transistor output
DC-coupled design with first class through-hole
components. No SMD transistors are applied. The high speed special
ACSS output stages are non-feedback and current driven design.
Almost all other designs need to convert the signal
multiple times from and to current or voltage, resulting in less
detail and less defined sound stage .
The output buffers are single ended FET. Two stages in
parallel to reach very low output impedance. All output stages are
in pure class A design without any (negative) feedback to achieve
purest and a real live sound reproduction.
The 4 OPA opampˇs are functioning as DC servo, this way no
coupling-capacitors are needed and DC output is automatically
biased! Resulting in a perfectly neutral sound.
There are no relays or other switches in the signal path
after D/A modules to allow the best and purest sound quality.
Heavy power supplies design:
DAC has 3 high quality low noise, low flux leakage, R-cores
In total 130W power to supply all digital parts and the
left and right analog boards. The DC power is distributed over 23
separate power rails. 20 groups are pure class A low noise regulated
power; fed by 3 groups linear power supplies.
This results in ultra-high speed and ultra-low noise
performance. Clean and independent power for all different parts to
achieve highest quality.
The Master 7 has completely separated power supplies .Digital, left and
right analog channel have their own dedicated transformer. All
boards and transformer compartment are separated by 5mm thick
aluminum plates for high isolation degree.
It improves the signal-to-noise ratio, isolate the
harmonic interference and reduce noise, which will make the sonic
background cleaner and blacker.
The Left and Right analog parts are placed symmetric
beside the digital board to keep the wires and distance identical to
ensure equal output performance on both channels .
The R2R DA modules are assembled between two aluminum
boards to avoid any RF interferences.