Thanks for selecting Questyle Audio CMA800R Current Mode Headphone Amplifier.
Quest is endless. CMA800R, Questyle new flagship current mode headphone
amplifier, is a dedicated quest for perfect sound.
CMA800R extends Questyle Audio’s outstanding Current Mode Amplification
technology, brings with less than 0.00038% ultra-low distortion, 650kHz wide
frequency, 118dB SNR. These parameters are far beyond any other headphone
amplifiers can achieve. Besides, CMA800R is the world first headphone amplifier
with Mono Full Balance function, in Mono full balance function distortion is less than
0.00026%. This low distortion will definitely bring a new innovation on the head-
phone amplifier.
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Current Mode Amplification , 0.00038% ultra-low distortion and ultra-high efficient
amplification
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Balance (XLR) input and Unbalance (RCA) input, support Mono Full Balance input
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Dual 6.35mm standard headphone jacks, a 3-pin Full Balance output, a pair RCA
Pre-amp output
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Provide Mono Full Balance function
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Provide Pre-amplifier output function
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Customized Plitron toroidal transformer
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Schottky rectifier, 22pcs 1000uF Nichicon FG Audio specific capacitor
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Amplification circuit all adopts DALE military resistors and WIMA capacitors
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All transistors are working in pure Class A status
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Perfect ON/OFF Anti-Pop Noise protection and DC protection circuit design
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Each device has its AP test report attached with User Manual
1) What is Current Mode Amplification Technology
(Global PCT No.:
PCT/CN2014/075775
)
Current Mode Amplification, means the amplification is processed in Current
Check List
Features
CMA800R
Power Cord
User Manual
Test Report
1pc
1pc
1pc
1pc
Front View
02
03
①
AC Power ON/OFF button
②
AC Power indicator
③
Output status indicator. “On” means device normally output to headphone,
"off" means abnormal. When AC power turns on/off, the anti-Pop noise protection
will delay output indicator several seconds to turn on, so as to protect headphone.
④
Balance input indicator
⑤
Unbalance input indicator
⑥
Input switch between balance and unbalance
⑦
6.35mm headphone jack
⑧
6.35mm headphone jack
⑨
Switch bar between standard Stereo and Mono mode. In standard Stereo
mode, CMA800R output to headphone via 6.35mm jacks. In Mono mode, 2pcs
CMA800R separately drive headphone left /right channel.
⑩
Full Balance Output, works only in Mono mode.
Volume control
11
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-
CMA 800R
Current Mode Headphone AMP
POWER
ON
OUTPUT
BAL
UNBAL
INPUT
OUTPUT
MONO
STEREO
FULL BAL OUTPUT
SE X 2
A B
1
2 3
6
7
8
9
10
11
4 5
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.
