1) What is Current Mode Amplification Technology
(Global PCT No.:
PCT/CN2014/075775
)
Current Mode Amplification, means the amplification is processed in Current
①
Right channel balance input
②
Right channel unbalance input
③
Left channel balance input
④
Left channel unbalance input
⑤
Full Balance input in Mono mode
⑥
Pre-amp output , Right channel
⑦
Pre-amp output , Left channel
⑧
Fuse
⑨
AC power socket
Rear View
Technology
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BALOUT R
BALOUT L
COAXIAL IN
OPTICAL IN
USB IN
OUT R
OUT L
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4
1
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8 9 10
Caution:
1) To protect headphone, please don’t frequently plug headphone in and out.
2) Please turn volume down before you change headphone.
version, instead of Voltage version.
Current Mode Amplification, same as Voltage mode, also take transistors as ampli-
fication components. But the amplification circuit loop is totally different from that in
voltage mode, in the whole closed-loop all the capacitors in between those transis-
tors which affects speed and bandwidth are working under ultra-low impedance, so
it can easily achieve large bandwidth and ultra low distortion.
2) Why we choose Current Mode Amplification
Low distortion and large bandwidth is what all amplifiers want to achieve. Only with
ultra large bandwidth and high speed processing can an amplifier wonderfully
process sudden pulse wave signal, and achieve real playback of music signal
speed and transparency.
Traditional Voltage mode amplifiers always cause a Transient Intermodulation
Distortion (TIMD), which brings a harsh “metallic sound”, badly destroyed the
sound. To eliminate TIMD, designers usually adopts feedback circuit loop (low
feedback, partial feedback or negative feedback) in hardware but these don’t
totally settle the problem, and cost is very high.
While Questyle gives up the traditional voltage mode format, designed with a
“Current Mode” amplification. When the components is working in Current mode,
amplifier Slew Rate (SR) achieves a linear increase as input signal amplitude
increases, it is in proportion to input signal amplitude. When it’s input with large
amplitude signal, Current Mode amplifier SR is much larger than traditional Voltage
mode devices, it can totally eliminate TIMD and ensures large amplitude signal
and low distortion real playback.
3) The world first headphone amplifier with "Mono Full Balance"function
CMA800R is the world first headphone amplifier that can work as Mono block. With
2 pieces of CMA800R both in “Mono” mode (device automatically turn to “Full
Balance” function), separately drive left and right channel of headphone, they
provides sound with unbeatable dynamics. Considering the Current Mode Amplifi-
cation technology, the Hi-end components applied, CMA800R will definitely be a
reference design for future headphone amplifiers. “Reference” is the definition of
“R”.
4) Rigorous Test and Sound Control
During the development stage, we use AP(Audio Precision) to analyze signal data
for objective test. Besides, we always keep our eyes closed in listening different
sounds for subjective feeling, so as to get unbeatable specifications. Each
CMA800R will be tested with over 30 factors of specification before being shipped
out. Test report will be put into carton box, and one copy be taken into our record.
