- Current Mode Amplification (CMA)
- Affordable featured all-in-one device
- Premium DAC section with True DSD
- Supports highest quality formats
- Separate pre-amplifier section
- 10mm Thick Aluminium cover and bottom chassis
What is it?
CMA600i follows the design of Questyle Audio’s flagship current mode DAC with headphone amplifier CMA800i and uses components of the same level. The headphone amplification of CMA600i produces ultra-low distortion to 0.00042% and ultra-wide bandwidth up to DC-600kHz (+0, -3dB), working under super-current and Class A state only, all of which makes CMA600i most outstanding at headphone amplification among the all-in-one models.
CMA600i’s USB input supports True DSD. Different from the commonly used DoP mode, CMA600i processes source data directly from PC and its hardware will switch to the True DSD channel when the system processes signals, strictly following the process of SACD playback.
CMA600i supports pre-amp unbalanced (RCA) and balanced (XLR) outputs. RCA pre-amp output level is up to 4Vrms, and XLR up to 8Vrms, which can meet the requirements of most power amplifiers for output level… Volume control employs an ALPS16 potentiometer working in analog mode only, supporting remote control. It is user-friendly for users of high-end active speakers.
CMA600i supports headphone balanced output, four groups of pure Class A current mode amplification circuits drive headphones in full balanced mode, doubling the output voltage, quadrupling the output power against that of single ended mode. It can easily drive headphones of low impedance and high sensitivity rating, able to reveal full performance of your headphones.
Performance of the circuit will be improved by Hi-end components. The sound quality and durability of CMA600i is guaranteed by using components like customized Plitron Toroidal transformer, WIMA capacitors, Nichicon FG capacitors, and Neutrik connectors etc., as well as applying more than 10 groups of separate power supply systems. CMA600i’s aluminum chassis is specially CNC tooled into “mutual-bit” structure, and its cover is only 10mm in thickness, helping to reduce its natural resonance to the lowest level. CMA600i’s feet are made of CNC-tooled pure alumi- num, which makes CMA600i strong and stable.
How does it work?
The CMA600i can also handle heavy loads with a 4-pin balanced XLR connection to maximize sound quality. The entry-level CMA600i utilizes a USB port that adopts a unique 3X Clock structure. This ensures a proper sync with the premium AK4490 32-bit DAC chipset from AKM. The chipset includes a newly developed switch capacitor filter “OSR Doubler” that greatly reduces sound degradation from noise shaping, achieving a flat noise floor up to 200kHz! The AK4490 chip obtains first-class sound performance by also reducing jitter and pre-ringing to undetectable levels.
CMA is the patented design used in Questyles flagship CMA800R headphone amp. Current mode amplification uses transistors to amplify. While the core amplification takes place in the current domain in pure Class A, the output stage can be changed to either class A or AB. The structure of the CMA amplification circuit is completely different from the traditional voltage mode amplifier.
The capacitance between the transistors, which affect the speed and bandwith, operate at a very low impedance. The full power bandwith of the entire amplifier loop is very similar to the bandwith of a closed loop. The SR grows linear with input signals and a strong, speed negative feedback loop. These features not only eliminate the TIMD, but also achieve amplification with a wide bandwith and ultra-low distortion.
What’s in the box?
- Power Cord
- CD-ROM with CMA600i Driver
- Remote Control
- CMA600i User Manual
- Test Report
- User Manual of Remote Control