Questyle CMA800R Golden – one of the best headphone amplifiers we have ever heard, regardless of cost. An absolute stunner!

The Questyle Audio CMA800R ‘Golden Series’ takes all the great technology found in the standard version but adds Roberts ceramic PCBs, for ultra-low signal loss and extremely stable transmission, and select components on the current mode amplification circuit. These additions combine to offer an exhilarating performance in sound quality and technical specification. The transparency of signal processing is improved significantly.

Questyle Audio’s outstanding “Current Mode Amplification”  technology (subject to a PCT patent held by and the core technology designed and developed by, Questyle Audio CEO and founder Wang Fengshuo) provides the airiness and musicality of a tube amp while maintaining the speed and accuracy of transistors.

What is Current Mode Amplification?

In current mode amplification, the signal is amplified by modulating current instead of Voltage. It is widely applied in the high speed communication industry and the video processing industry, but it is Questyle Audio’s patented technology as applied to headphone amplifiers.

Why We Choose Current Mode Amplification?

Low distortion and wide bandwidth are the goals of all high performance amplifiers. Only with ultra wide bandwidth and high speed processing can an amplifier wonderfully process sudden pulse wave signals, and achieve realistic playback of music signal with speed and transparency.

To achieve this Questyle Audio abandoned the traditional voltage mode format and developed “Current Mode” amplification. When the component is working in Current mode, the amplifier Slew Rate (SR) achieves a linear increase as input signal amplitude increases, in direct proportion to the input signal amplitude. When receiving a high amplitude signal, a “Current Mode” amplifier’s SR is much faster than traditional Voltage mode devices, totally eliminating TIMD and ensuring a high amplitude signal with an extremely wide linear bandwidth and an almost distortion free realistic playback.

Work Principle

To maximize accuracy, current capability, and consistency, Questyle Audio’s Current Mode Amplifier employs all discrete componentry, in a Class A configuration. To insure maximum compatibility with source units and speakers (headphones), Input and Output both work in voltage mode. From the diagram we can see, input signal will travel first to VCCS, voltage mode is converted to current mode here, then it goes to Ai for amplification (in current mode), next it goes to I/V converter to become voltage mode again, and then is output to OPT stage to drive headphone

    Gain：  15.5dB

    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)

    Sensitivity：  1.2Vrms

    Impedance：  47KΩ

    Input：    XLR stereo, RCA Stereo, and XLR Mono Full Balance input

    Output：Dual 6.35mm Stereo headphone Jacks,  XLR Mono Full Balance output, RCA Pre-amp output

     Work Status：Pure Class A

    Voltage： 100-120Vor 220-230V, Internal switchable

    Power Consumption： 13W

    Dimensions：  330*300*55 mm

Questyle CMA800R Golden