Price: (Exclude shipping cost)
(Smooth edition) : USD1850
( Assemble 8 pcs Toshiba every pc with 15A /150W output transistors .For who like the
sound warm and smooth )
(Neutral edition) : USD1899
( Assemble 8 pcs ON Semiconductor every pc with 15A /230W output
transistors .)For who
like the sound neutral and transparency. )
The unit has included below remote
Custom order :
Custom order one or some inputs without volume
control , work as the pure power amp for speaker and headphone.
Please note: Before the Master 9P release , a customer
advised the Master 9P Headphone output sockets are the 4pins XLR X3 / 6.3MM X1,
after shipped some units the customers said least 30% hifiers still
apply the dual 3 pins headphone output so the Master 9P will
assemble 3pins XLR X2 / 4pins XLR X1 /6.3MM X1
Please send your address, name to
firstname.lastname@example.org get the quote.
Is the 70W+70W enough?
The Master 9P has 70W+70W at 8 ohms, even with 60W
output , the THD+N still low to 0.055% at
1KHz and 0.004% at 20KHz, much lower than some power amp at 60W
output but declare 150W max power .
Usually the transistor built in power amp
had been recommend the actual output power is around 1/5 to 1/3 of
the max power output for keep the distortion as low , so the Master
9P can work as well as some 200W power amps .
For the home audio system, if the
speaker with lower than 86DB sensitivity , the listen room usually
around 20 square meters , if the listen room is larger , the speaker
usually has higher than 88DB sensitivity , for these situations, 1W
/ each channel avg. power already can make the speaker for normal
listen , even with the quite loud listen , 5W / each channel avg.
power already can boost close 100DB on the 88DB sensitivity speaker
. In the case the Master 9P still has 14x times spare power.
Of course there is no doubt for drive any
Real dual mono design
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
sound like the pure class A design but without the high heat of
the pure class A design .
Applies 8 pieces of ON Semiconductor transistors ,every
piece has 15A/230W performance (Master
(8 Ohms) output, 14W X2 (40 ohms) .
The capacitance of the whole machine reaches as high as 100,000 uF,
with two circle core in total 600W power ,which is larger than
some 200W power amps .
A total of 4 groups of high-quality class A parallel connection
PSU's supply the gain stages.
Two gain modes with 100 steps exponent character volume control ,
high gain has 34DB, low gain has 20DB, no problem drive any high or
low sensitivity headphone and speaker.
5 groups input: RCA X2, XLR X2, ACSS X1
Speaker output *1 pair
Headphone amp output: 3pins XLR X2 / 4pins XLR X1 /6.3MM X1
Headphone output options with neutral and
simulate vacuum sound for customer selects on the front plate
The non negative feedback output
drive stages had applied "Linear Fidelity" technology :
The Master 9P 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
playing and edited together.
Below diagrams had
the distortion on the Master 9P.
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 9P 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 9P 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 of the USD6K amp has 0.015% distortion at 20KHz , the below diagram has
0.002% 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 20W (<0.055% at 1K,
<0.002% at 20KHz)
with 60W output , it still offer the low distortion.
THD+N at 8 ohm 60W (<0.055% at 1K,
<0.005% at 20KHz)
The Master 9P has very wide frequency
band that allow the signal output has very low phase distortion ,
offer the most transparency but analog sound . But please not,
you must match it with the good DAC and source and speaker /
headphone , because it is so revealing , it can't give you the good
sound if match with the USD30 DVD player .
Frequency band at 8 ohm 1W
(-2.5DB at 200KHz)