Questyle CMA800R Amplifier
Questyle CMA800R Amplifier
Quest is endless. CMA800R, the flagship Current Mode Headphone Amplifier of Questyle Audio, is a dedicated quest for perfect sound.
CMA800R extends Questyle Audio’s outstanding Current Mode Amplification TM technology, it provides 0.00038% ultra-low distortion, 650KHz wide frequency, 114dB Signal to Noise Ratio. These parameters are far beyond any other exist headphone amplifiers can achieve. Besides, CMA800R is the world first headphone amplifier support Mono Full Balance function, in full balance mode its distortion is even less than 0.00026%! CMA800R, will definitely be a milestone of headphone amplifier.
What is Current Mode Amplification?
Current Mode Amplification, means the amplification is processed in Current version, instead of Voltage version. It’s widely applied in High speed communication industry and video processing industry,but it’s Questyle Audio’s patent technology to apply it into headphone amplifier.Current Mode Amplification, same as Voltage mode, also take transistors as amplification 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 transistors which affects speed and bandwidth are working under ultra-low impedance, so it can easily achieve large bandwidth and ultra low distortion.
Why we choose Current Mode Amplification
1,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. Like Questyle CMA800i, designed with ultra-low distortion as 0.00026% and ultra large bandwidth as 850KHz.
2,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.
3,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.
CMA800R Work Principle
Since 1989 in the 87th AES forum, when Dr. D.C Wadsworth first point out current mode circuit in audio can achieve ultra-high speed, ultra-low distortion function, people start ceaseless dedication on current mode amplification. So far some brands created CAST (Current Audio Signal Transmission) technology, SATRI technology based BPM7110 modular, etc. These are pioneers on developing current mode technology application on audio. But they are mainly “non-feedback” mode, mainly for current mode “transmission” rather than amplification. Questyle is different, we specially focus on “amplification” instead of “transmission”, so CMA800R provides much more outstanding specification and sound performance.
Max Output Power: 180mW (7.5Vrms) @300Ω, standard Stereo Mode
710mW (15Vrms) @300Ω, Mono Mode
SNR: 114 dB, standard Stereo Mode
118 dB, Mono Mode
THD: +N 0.00038%@1kHz, 300Ω standard Stereo Mode
0.00026%@1kHz, 300Ω Mono Mode
Frequency Response: DC-200kHz (+0, -0.3 dB); DC-650kHz(+0, -3 dB)
Input: XLR stereo, RCA Stereo, and XLR Mono Full Balance input
Output: Dual 6.35mm Stereo headphone Jacks, XLR Mono Full Balance output, A pair RCA Pre-amp output
Work Status: Pure Class A
Voltage: 100-120Vor 220-230V, Internal switchable
Power Consumption: 13W
Dimension: 330*300*55 mm