Current Mode Amplification
Current Mode Amplification , referring to a Current Mode Audio Amplifier, is a patented technology of Questyle Audio. It is a state-of-the-art technology of audio amplification different from the traditional audio amplifier. As the “engine” of audio system, Current Mode Amplification, featuring a fully discrete and topological structure, achieves ultra-high sound performance close to recording scene that makes audience truly moved. Meanwhile, based on Current Mode Amplification technology, users can get much better listening experience than common devices even they match with their own headphones or speakers rather than the original collocation.
Current Mode Amplification features the use of transistors to amplify and a fully discrete structure, to wit: voltage input and output, while the core amplification takes place in the current domain operating in a pure Class A state. It is completely different from the traditional voltage mode amplifier in the structure of the amplification circuit. Current-mode audio amplifiers affect the speed and bandwidth of the transistor-level capacitance between the low impedance nodes, not only completely eliminates the transient intermodulation distortion (TIMD), but can easily attain ultra-high bandwidth (full power bandwidth of 500kHz ) and ultra-low distortion (lower than 0.0002% THD+N, challenging the physical limits of audio testing). The Current Mode Amplification technology can be used for amplifiers of any power level (10mW-2000W) and of any size (thousands of square centimeters for some professorial amplifiers).
Pure Class A BIAS Control
Questyle Audio makes use of the Pure Class A BIAS Control System to ensure that Current Mode Amplifiers operate only in the state of pure Class A when driving different loads (headphones or speaker), which achieves perfect listening experience and outstanding performance.
Questyle’s BIAS Control System is based on the Current Mode Amplifier. According to users’ settings, it operates through an isolated circuit and uses a processor to control, adjust and test the bias values of the output stage of current mode amplifiers, which ensures the output stage to operate in the state of pure Class A, and achieves the excellent system experience by the exact match with your headphones. Compared with traditional technologies like super Class A or automatic bias Class A, Questyle’s BIAS Control System is more direct and thorough, and there is no negative effects or delay problems. It can perfectly drive headphones or speakers of different specifications and easily give full play to their abilities.
Digital Signal Processing: IIR Digital Filter
Questyle IIR Digital Filter completely eliminates the pre-ring and produces natural sound.
More than 99% of digital audio in the world use FIR (finite impulse response) digital filters. The pre-ring that FIR digital filters add to impulse wave could be obviously tested and heard, which produces unnatural sound that ruins the enjoyment in music. While Questyle Audio’s advanced technology of digital signal processing – IIR digital filter, completely eliminates the pre-ring from impulse wave, producing more ethereal and natural sound.
5G High-end Wireless Audio System
If you want to extend the unique listening experience to your home or car, transmitting the high resolution audio via common Bluetooth technology has the limitations of short distance and lossy compression sound quality. But it will be easily cut off and unstable caused by environment if you transmit the lossless audio via WiFi technology. Besides, these traditional wireless technologies have the problem of difficult synchronous. Engineers have to design the stereo and multi-channel terminal speakers together, but this can not restore the sense of space and direction of the scene which makes the atmosphere greatly reduced.
Questyle Audio believes that the wonderful sound should not be limited, so they research totally different 5G Wireless Audio System aiming to high performance audio. The unique technology works at ultra-high RF frequency band with independent protocol stacks rather than the router, which essentially solves the problems of interference and instability that the traditional technology has. Meanwhile, high-bit stream can easily transmit lossless audio, support the amazing 8-channel realtime transmitting and put speaker terminals of different channels in a reasonable position. Questyle 5G Wireless Audio technology which has also passed the EU CE and the United States FCC electromagnetic compatibility certification, achieves perfect wireless audio extension experience.
True Direct Stream Digital
True Direct Stream Digital
Questyle patented “True DSD” technology processes DSD signals without any PCM converting and provides the original DSD signal processing, which is fundamentally different from the traditional DoP and Native DSD. It truly restores the experience of DSD audio files.
When the system processes DSD signals, hardware mode switches to the True DSD channel and the signal processing is done under the original DSD format. In this case, all the digital filters as well as digital volume control are bypassed, strictly following the standard processing of SACD playback.
3x Clock USB Asynchronous Transmission
To avoid Jitter which the traditional design of a single clock with PLL will produce, Questyle Audio employs a three-clock integrated circuit with FIFO asynchronous architecture, ensuring accurate sound and quality playback of digital audio files.
3x clock asynchronous structure: the first clock is in charge of the system, the second clock drives sampled signals of 44.1kHz and multiples of 44.1kHz, and the third one drives sampled signals of 48kHz and multiples of 48kHz, as well as DSD signals.
Dual Clock Integral Upsampling
Questyle Dual Clock Integral Upsampling with two clocks of ultra-low phase noise automatically identifies the current sample rate and upsample integrally, eliminating errors, which overcomes many deficiencies of the traditional upsampling circuit .
For most of the upsampling design, no matter how much the sample rate is, it upsamples at 192K other than re-sample integrally, which will cause timing errors and distortion, lowering sound quality. While the dual clock integral upsampling is quite different, with extremely low phase noise, the processor automatically identifies the sample rate and upsamples integrally, which eliminates timing errors and improves the sound quality.