The Master 2A is
a 100W pure class A power amp, when it working , it can achieve 50
degree centigrade , please place them at the air flow area .
What different to the
The Master 2H is a class A power amp with
the dead neutral sound flavor.
The Master 2A is a 100W pure class A amp , the
pure class A design make the sound slight warmer and smoother . We
had tuning the Master 2A sound from ACSS input is close neutral but
a tiny warmer and smoother , and the sound from XLR input is more
warmer and smoother .
Advice on the selection:
The Master 2H suite the customer who like the
dead neutral sound much .
The Master 2A suite the customer who like the
sound warmer and smoother, or much love the pure class A amp .
DC blocker available for custom
Because the product has the low impedance transformers design , if
the power line (120V or 230V) has serious disturb , usually will has
the low voltage DC in the power line, cause the transformers have
the vibration and cause the noise.
Even though in the same serious disturb in
the power line , the high impedance transformers design can without
vibration and noise , for example the R core, EI core or high
impedance design O core transformers.
But for the power amp, the high impedance
transformer design has effect and degrade on sound dynamic, bass
impact and control .
Because the serious disturb power line is
rare, based on the customers feedbacked, it has around 10% users
meet with serious disturb , so our power amps have not include
the DC blocker . If customer has experience on vibration and noise
in last power amp model, customer can custom order the DC blocker ,
it can kill 1.2V DC of the power line which is enough for most case.
Price is USD80.
The non negative feedback output
drive stages had applied "Linear Fidelity" technology (Appling for
The Master 2H had applied the "Linear Fidelity" technology on the
output drive stages . The output drive stages had not negative
feedback but can keep the distortion low and steady, and had the
ultra excellent linear performance.
In some lot power amp designs, the distortion
had big different level on different power output level , even on one power
output level, the full frequency band's distortion level had quite
different , especial the low and high frequency .
The blue line of below diagram show the distortion to
frequency at 8 ohm 20W output of an well known power amp which worth around USD10k.
The below diagram show the most musical instrument frequency bands .
The frequency band had cover from 20Hz to 4KHz .
Different distortion must effect on the
sound . For example, if playing piano music recorder, cause by the
larger different distortion on the frequency band, you can hear the low
frequency band like playing a brand A piano, the middle frequency
band like playing a brand B piano, and the high frequency brand like
a brand C, the music recorder like the different brand pianoes
Below diagrams had
the distortion on the Master 2A.
The negative feedback applied,
most is for reduce the distortion.
Some people dislike the
negative feedback design on the power amp, it reduce the distortion
but make the listen unpleasure.
The negative feedback power amp
had good distortion result on emulational load measure, but while
connect the real speakers, the electric potential of the speaker can
through the feedback loop feed to the amp input stages cause the
The negative feedback power amp
even reduce the distortion , but the distortion increase while
output power increase, this cause the larger dynamic music sound
become harsh and fire to your face while listen the music.
Usually the non negative feedback design has high distortion and
difficult to control, especial the drive output stage which is work
under strong current state.
In the Master 2A design, the
gain stages have applied the ACSS technology, it is the non negative
feedback design but it's native advantage has very low
The output drive stages had
applied the " Linear Fidelity " technology .
overall design in the Master 2H is non negative feedback design.
the diagrams, the amp has quite flat and steady distortion on the
frequency band from 20Hz to 5KHz, keep the same sounding character
while playing the musical instruments .
distortion roll off a lot start at 5KHz, even lower than some amps which is
depend on the negative feedback , it obvious show the supper linear
performance of the amp.
Compare the diagram, the upon
diagram has 0.015% distortion at 20KHz , the below diagram has
0.0018% distortion on 20KHz.
The ultra low distortion had not
depend on the negative feedback, but depend on the ultra linear of
the amp, so it's sound very transparency and analogue.
On the different output power
level , the amp has similar distortion level, while listen with
softer and dynamic music, it offer the same sound character without harsh .
THD+N at 8 ohm 10W
THD+N at 8 ohm 25W
THD+N at 8 ohm 50W
design, the gain stages and pre-driver stages work in
class A, built with discrete analog stages without any OPA
or coupling caps in the signal channels.
The output transistor stages have supper excellent linear, it
work with 100W pure class A station.
2 analog inputs: XLR
Applies 80 pieces of ON Semiconductor transistors. Supports
(8 Ohms) output.
The capacitance of the whole machine reaches as high as 260,000 uF, with two
850W circle core and two R cores transformers (Total
1800W) and separate power supplies
for the right channel and left channels.
A total of 4 groups of high-quality class A parallel connection
PSU's supply the gain stages.
Applies all audiophile grade components, including DALE resistors, WIMA caps, custom order NOVER (UK brand) caps, all audiophile grade
input & output sockets and gold IEC socket.