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Detail of the Current Conveyor Technology
Unique real non-feedback ACSS headamp/preamp
technology:
HE-9 LE built in a true balanced design
applying the newest ACSS design . It seems complex , but in fact they are
the most simple design the world has ever had , their a lot
components to process the power supply. The HE-9 LE built in amp only has a
single " voltage" gain stage to process signals, but works in ACSS mode
so in fact it is a current gain stage instead of voltage gain stage,
whereas normal OPA chips already include two or three voltage gain
stages. The simplest and shortest signal journey brings out the most
neutral and least colored sound.
HE-9 LE applies ultra-low distortion
single stage ACSS amplifier and soldered directly on the motherboard .
The gain stages and the diamond cross output stage working on
pure class A state.
The ACSS is
a non-feedback
technology made with fully discrete amplifiers. Most people know the
global
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.
All signal gain is in current, achieved
by the unique, superb open-loop multiple output current mirror.
Incomparably precise and ultra-low distortion in the gain signal is the
result. The signal path is balanced throughout and all transistors work
in class A mode.
HE-9 LE applies
four channels of non-feedback output stages composed of
8 pieces of transistors, every piece has
15A/150W performance. The
capacitance of the whole machine reaches as high as 36,000uF.
Three R-core transformers are used with
total power of 145W.
4 group class A PSUs power supply for Left and Right
audio signal amps .
Unique I/V
conversion volume control technology:
The volume control is also different from conventional
technology. Conventional volume control technology is
the volume control implement in the analog amp
input stage through a volume pot to reduce the signal . The
volume pots quality effect the sound quality direct , the low
quality volume pot cause lost the detail and channels imbalance
cause the soundstage distortion . Even the high
performance volume pot ,in the attenuation then gain the signal
mode ,still cause the detail lose and cause the S/N worst .
In
the HE-9 LE, we applied the I/V conversion volume control ,
the volume control just a
variable passive I/V conversion place at the ACSS amp output ,
where the output is the current signal, not the voltage signal. The
volume control is I/V conversion, and the volume depends on the
current (I) conversion to the voltage (V). (Like R-2R D/A chips
output passive I/V conversion)
It can keep the signal frequency band flat and
not lost any detail.
It can't degrade on sound
quality in every volume level . After the volume , there are
diamond cross output stage offer the
very low output impedance .
The volume
control quality is much important in the real balance gear . It must guarantee the
four channels signal control exact to achieve the performance of the
real balance gear . If the cool and hot of the balance signal
can't guarantee exact, the balance output will has large distortion
cause the sound quality and performance even much worst than a
single end gear , waste the balance gear design and the cost.
In HE-9 LE
is applied a four channels digital control relays based volume
control, through changing the
tolerance 0.05% resistors to control the volume for avoid channels
imbalanced ,achieve the best performance and sound quality of
the gear.
HE-9 LE have 100
steps volume control, applied Supper Exponential Volume
Characteristic, easy match the volume with different power amp
and speaker .While change the volume, the different relays break or
close, it may had slightly switch sound on output and disappear
while stop change the volume.
Supper Exponential volume characteristic The Volume steps comparison to normal volume knob
Shield:
HE-9 LE has complete separation of left, right
amplifier channels, and transformer, even the 230V / 120V
power input lines had shield in the two thick aluminum boards .
HE-9 LE uses
heavyweight all-aluminum chassis to prevent the
eddy current of transformers from interfering on circuit board.
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Summarize
