Into this mix now steps Questyle.
Questyle has been very effective with its headphone offerings — and the CMA800R amplifier ($1,999) has earned some very favorable attention from our friends at Audio-Head, 6moons and many others. The key (well, among other things) is that the brand uses an unusual method for handling the amplification, which they call “current mode” (with a patent pending). From the website:
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.
Got all that? Great.
The interesting part, to loop back in the intro, is that this technology is now coming to their upcoming DAPs, the QP1 (TBD, but ~$600) and the QP1 Pro (also TBD, but ~$900).
The players will support file resolution of up to double-DSD (and everything below that) and all file formats. The chip is the same as found in the top-of-the-line Astell&Kern AK240, a Cirrus Logic CS4398 (well, one of them — the AK240 uses a pair). Both the QP1 and the Pro will feature a pair of MicroSD card slots, for up to 256G of storage. Beyond that, the two units are rather similar and will offer the same functionality. The difference will come down mainly to parts — at 32G, the Pro will have four times the internal memory of the QP1, and will also feature a host of subtle parts upgrades across the output path, all adding up to a superior sound. Questyle VP Bruce Ball also mentioned that there may be a few more cosmetic changes to the two units between now and general availability in late April, possibly including an upgraded screen. We’ll have to wait and see on that — but not long, as Bruce plans to show fully-funcitonal pre-shipping units at CanJam SoCal in late March out in Newport Beach, CA.
So, what else was new? Glad you asked.
CES also saw the debut of the CMA800i ($2,495 — available now), an “integrated” product that combines the functionality of the CMA800R amplifier and the CAS192D ($1,999) digital audio converter in one chassis. Bruce describes this as “80% of the CMA800R and CAS192D for just over half the price”. That spells “value” to me. Brian will be getting a unit for review, so stay tuned for that.