Xmos U8 Introduce and drivers
combo 384 Intruduce and driver download
(For the unit with the Amanero Combo384 upgrade module)
Audio-gd products had
design and test based on the AP SYS-2722 (The top-drawer
professional equipment in world)
Different to the last
generation NFB-1 (2016):
The newly designed ES9028Pro can setting the built
in filter parameter , it can auto detect the input signal DSD and
remove the switch noise . In this design, the input signal had less
signal journey feed to the ES9028Pro , improve on the sound quality .
Multi-ply shield boards to isolation the power input socket , transformer, power supplies,
digital part and the analog part .
Fully Balanced Discrete design built by discrete analog stages without any OPA
and coupling caps in the signal channels .
Non- feedback ACSS analog output stage .
LED display avoids RF disturbance for better
R-core transformers and Hi-fi grade parts like DALE resistors, WIMA
A total of 5 groups class A parallel mode PSU power supply for all digital and
analog circuits. There is another one linear PSU power supply for
the control parts .
4 digital inputs:
USB / Optical / Coaxial RCA / I2S
Support DSD and DXD through USB and I2S .
DAC output: XLR / RCA / ACSS
User can change the digital parameter setting
Detail of the Current Conveyor Technology
Simple and short signal transfer is best:
The NFB-1 applies the newest ESS high-end Sabre32 DA chip
ES9028Pro which can support up to 32Bit/384KHz input .
in voltage output model , there is -12DB THD+N worst , to be
achieve the best performance of ES9028Pro , must work in current
output model .
In some other ES9028Pro built in DAC design ,
ES9028Pro output signal have to through 3 step OPAs implement analogy
signal process .
had different design , applies Non-feedback ACSS
design. The ES9028Pro feed to the ACSS
circuit by balanced model without any OPAs .
The ACSS circuit naturally working in
current model and have design difference current input , it can
transfer the ES9028Pro current signal to output and implement the I/V
conversion in current model in one ACSS amp . And this ACSS amp only
have one current gain stage , the ES9028Pro output signal only through
one stage can arrive the output stages .
The shortest signal journey can reproduce the best
detail and dynamic, and almost without sound coloration , It can
show the real performance of the ES9028Pro .
So our ACSS design is the best combo with
ES9028Pro achieve the best performance .
The ACSS also is a non-feedback
technology made with fully discrete amplifiers. Most people know the
feedback design can offer better specs in test measurements, and
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.
The output buffers are
Non-feedback pure class A FET design.
The DAC is without couple
caps to avoid coloration. There are two OPAs built in as the DC serve to
keep the DC offset .
The 32bit / 384K USB interface
outputs a I2S signal to ES9028Pro .
Multi-ply Class A power supplies are the key of sound :
applies the excellent DA chip ES9028Pro and excellent analog
output stages, but these are not the only keys of the best sound.
The power supply is most important. Even applying the best DA chip
and the best amp, if matched to a average power supply, the total
sound may still be average or sound musical but can't be neutral and
detailed. That is why it is easy to find hi-end grade gears maybe
without the best chips , but with plenteous dedicated
DC supply circuits.
uses A total of 5 groups class A PSU power supply for all
digital and analog circuits.
To achieve high S/N, the
control circuit is powered with separate regulator.
Diagram of the Class A PSUs for analogy parts Diagram of the
Class A PSUs for digital parts
The Multi-ply shield boards for avoid the interrupt:
The NFB-1 (2016) had built in Multi-ply shield boards, to separate the transformer, power supply, digital parts and
analogy parts for avoid the different parts had disturb . Even
though the power input IEC socket, it had hide in a copper shield
Built in Hi-End grade parts :
have built in most high end grade parts, like the DALE resistors
(USA), WIMA caps (Germany) and NOVER parts (UK) .
These parts have through long
term practices and consider have least sound coloration .
Built in high end grade parts
have not warranty have the good sound , but the best
technology design with high end grade parts can have the high ended
sound quality .