QA661 Hi-Fi Digital Audio Player & USB Bridge to Computer

QA661 Hi-Fi Digital Audio Player & USB Bridge to Computer

QA661 is a Hi-End digital music transport, It is based on the QA860 digital music player's digital output port with improvementon the digital output circuit, We spent over 2 years on developing and continuing optimizationthrough testing more than 10 major hardware version. This is a true competitor to most of the desktop Hi-End CD players, and able to boost the performance of your whole system with its ultra-high-fidelity digital output that ensured by the single threaded software framework, complicated power supply systems and clock circuits.

Our target: Perfectly and accurately recovery for the music recordings, and deep dark background .

The single threaded software framework

QA661 implemented the latest version of QLS-HiFi s unique proprietary technology C the single threaded software framework. This technology ensured ultra-low jitters and high accuracy in playback of digital music, and set the new standards for the digital output of a digital music player at some points.

Why we spent over 3 years of hard work and several dozen thousands of cost in developing this software framework by creating several dozen thousand lines of completely new code from zero? Because we believe the primary task for a digital music player is high-fidelity sound recovery. QA661 is the result of our persistence in pursuit of our belief on HiFi.

The vital aspect of single threaded software framework is running different programs one by one in serial processing mode, and audio program is on the highest priority level. Anytime if the audio playback program calls for reading and decoding audio files on the SD card, the audio playback program overrides all other programs in running for the call right away. Once the audio data length decoded from the audio files reached a set point, this data segment then is sent to the I2S buffer automatically with overriding all other microprocessor commands. The microcomputer system reserves 200%more of the normal audio playback program running time from system for sending the audio data segment to the I2S buffer according to the precise calculation by our engineers. In order to providing enough time resource for audio playback program some other functions such as remote control are kept out from the main microprocessor, and carried by other independent chips. The whole process therefore providing a significant improvement in reducing jitters and streaming music data flow accuracy.

Digital processes may represent a sound exactly. Just as a professional taster might select the exact vintage after careful inspection, so the computer will read, and re-read a disc as many times as it needs to, to ensure it has the exact sound. This process is more accurate than a CD player may achieve: the player will read through only once. It does not have the benefit, as the taster does, to go back and resample.

24Bit / 192KHz wav and DSD Support

QA661 supports Studio Master wav files in 24Bit / 192KHz and DSD64 / 1Bit / Stereo. DSD files can be streamed out of the digital output in DoP format.

QA661 Also is a XMOS USB Bridge to Computer

The QA661 also is an asynchronous High Speed USB to digital audio interface that extracts the highest possible audio quality from computer audio sources.

The QA661 is have High Speed USB 2.0 input data connection C Sampling rates up to 192kHz and word lengths up to 24Bit are supported.

Great care was taken in the design of the QA661 to isolate the noisy computer / USB environment from the digital audio output. The USB receiver and processing are powered by the computer, while the output line drivers are powered by a separate isolated linear power supply.

The QA661's USB is designed to work with both Apple Macintosh and Windows PC computers. Microsoft Windows PC s require the included Windows driver which works with Windows XP, Vista and Win7 / 8 / 10.

Features & Specification

Streaming music data flow from the SD card to the digital outputs with Ultra-low jitters and high accuracy by the single threaded software framework together with 2 sets of independent sampling clock circuits (44.1K / 48K) and mono-system-aspect-design in separated power supply systems and grounding systems.

Audio format supported:

  WAV 16 / 24Bit, 44.1~192kHz.

  AIFF  16 / 24Bit, 44.1~192kHz.

  FLAC  16 / 24Bit, 44.1kHz~48 kHz, compression level 0~8.

  APE  16Bit, 44.1kHz, compression level fast and normal.

  WAVPack  16Bit, 44.1kHz, compression level fast mode and high quality.

  ALAC  16Bit, 44.1kHz

  MP3  16Bit, 44.1 / 48kHz, 96k bps~320k bps, CBR / VBR / ABR encoding.

  CUE  ANSI / UNICODE / UTF-8 Encoding.

  DSD  DSD64 1Bit, Stereo --- DIFF, DSF, SACD ISO.

Digital Output: (outputs can be used at the same time without interfering each other).

  - Optical

  - EBU / AES

  - RCA Coaxial

WordClock Output: The QA661 is including the low-jitter wordclock output for direct synchronizing external d / a converters. (The word clock output is valid only for the internal SD card player mode, invalid in the use of USB input or external coaxial input.).

External coaxial input ---QA661 has an external coaxial input port, which can be used for process the input signal and driving the output, thereby improving the sound quality.

Support SD / SDHC / SDXC up to 256GB SDXC with FAT32 (Upgradeable with further firmware upgrade).

OSD supports English, simplified Chinese and traditional Chinese.

Support Software(Firmware) Upgrade.

Output voltage: Coaxial (0.5V p-p), XLR (5V p-p balance).

Digital output formats: PCM / Dolby Digital / DTS.

Power: 9-11W.

Input Voltage: AC 110V and AC 220V selectable.

Dimensions: 215mm x 315mm x 100 mm.

Weight: 4.1KG.

Internal PCB board

In order to improve the quality and sound quality, components are subject to change without notice.

The following items are included with your Order

01. QA661 Player x 1.

02. Remote Control x 1 (Not include AAA battery for remote control )

03. Power cable x 1

04. 16GB Class10 SDHC Card x 1

05. SDHC SD USB 2.0 Memory Card Reader x 1 (Card Reader not Warranty)

06. USB Cable x 1

07. English User Guide x 1