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
The single threaded
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
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 (becoming a ¡°bridge¡± between
your computer and your DAC.)
The QA661 also is an asynchronous High
Speed USB to digital audio interface that extracts the
highest possible audio quality from computer audio
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.
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
Support SD / SDHC / SDXC up to 256GB SDXC with FAT32
(Upgradeable with further firmware upgrade).
OSD supports English, simplified Chinese and traditional
Digital output formats: PCM / Dolby Digital / DTS.
Input Voltage: AC 110V and AC 220V selectable.
Dimensions: 215mm x 315mm x 100 mm.
( Internal AAA battery is not included )
Internal PCB board:
( In order to improve the quality and
sound quality, components are subject to change without
The following items are included with your Order:
QA661 Player x 1.
Remote Control x 1 (Not include AAA battery for remote
Power cable x 1
16GB Class10 SDHC Card x1
SDHC SD USB 2.0 Memory Card Reader x1 (Card Reader not
USB Cable x1
English User Guide x1
Price: USD $649.99 ( Exclude shipping cost ) (
In Stock ) At the time of purchase, please indicate the following: Your couftry's voltage specs.
Payment methods 1: Direct
remittance to PAYPAL, Our PayPal Account: firstname.lastname@example.org
We will send good by DHL / TNT / EMS Expres, and we
will declare the sending for gift with a low value(For
example: USD $100.00), to reduction reciever side to pay
tax or try to avoid reciever side to pay tax.
If the list have not include your country, Please
contact us for get your shipping by E-mail.
Payment methods 3: You alse can pay to our bank Accout:
Our Bank of China Account:
A/C NO: 4766938-0188-129144-0 IN A/C WITH:
BENE¡®S BANK: BANK OF CHINA SHENZHEN BEI FANG BUILDING
SWIFT CODE: BKCHCNBJ45A ADD:
1/F,BEI FANG BUILDING,SHEN NAN
POST CODE: 518033
Tip: The beneficiary name should be TANG YAN, Not is QLS
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recipient address, zip Code, contact phone number.
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