QA350 is an all-in-one portable SD card HiFi wav music
player based on QA550. In contrast to QA550, QA350 has a
high quality DAC and headphone amplifier integrated into its
tiny body. The headphone output is able to drive most
16-300Ω headphone in the market.
QA350 employs 7.4V Li-polymer battery normally used on
aircraft models. This type of battery has very low internal
resistance and high discharge rate. The momentary discharge
current is able to reach couple of amperes easily. This gave
QLS design team the opportunity to get rid of the voltage
boost circuits and voltage reversal circuits that are very
common to see in the portable players. Therefore QA350 is
able topresent the music with enhanced bass and transient
response, as well as ultra-low high-frequency noise and full
Compare to QA550,more improvements on the LDO power supply
circuits and PCB optimizations have been made for QA350,
thus improved the sound quality little by little with every
single small step.
The good thing kept on
QA350 is the single threaded real time audio play program
with SD card. This unique technology is QLS’s guarantee to
be HiFi. It is without any interrupt to steam the music
files, other control functions are carried by another
separated microprocessor. It achieved extremely high
accuracy on the time sequence when streaming music files
from the SD card. Moreover a special customized 11.2896 2ppm
TCXO with jitter lower than 10PS is used as the main
sampling clock.Thus the whole system reached our goal on the
recovery of musics.
- Support format: 16bit 44.1K WAV (the
same with CD ripping and file format).
up to 32GB with FAT16 and FAT32, 90 folders up to 900
- Digital output chip: CS8406.
- DAC Chip: Wolfson WM8740.
- LVP: AD8656.
- Headphone Amp chip: MAX9722A.
- Digital Coaxial RCA
- Digital Optical(round)
- Analog Line out: 2V (RMS), frequency response
20Hz-20KHz, SNR> 100dB, Distortion <0.005%
- Headphone out: 130mW/32 Ω, 70mW/16Ω, Frequency
response: 20 Hz-20Khz. THD + N (total harmonic
distortion plus noise): 0.009%, matching impedance:
16 ohm --- 300 ohm
- Battery Type: 7.4V Li-Po battery of
Model General Specifications, maximum size: 55mm * 31mm
* 16mm; the capacity is usually among 800-1100mAH.
- Battery life: 6 to 8 hours.
- Charging time: 1.5-3 hours (when
charging, playing music can available powered by the
external power supply)
110-240VAC, 800mA/S, balanced 2 cell charger.
120-150mA (LED backlight OFF), 150-180mA (LED backlight
ON), 9VDC external input.
- Dimension: 135mm * 78mm * 27mm
(excluding the output socket, switch, button, etc.)
150mm * 78mm * 30mm (with all the sockets, VR button,
- Package size: 235mm * 135mm * 55mm
- Single Weight (with battery): 0.3kg
- Packing Weight: 0.75kg
WAV files are the favourite format choice
of people who can't bear the sonic difficiencies of the
lossy compressed MP3 format yet want to store, preserve and
playback treasured CD collections from their computer hard
Up until now, these people would simply be
content to use their computer as their main Hi-Fi source
Whilst excellent at converting CDs to WAV
files, the PC / Mac is still not the ideal music plackback
device. The majority if PCs don't have the best
powersupplies and are absolutly packed with noisy,
interference inducing components. Multiple noisy fans buzz
away constantly and due to components fighting over limited
resources, "pops" and stutters on the audio are not
In these days of hugely expensive utility
bills, the electricity consumed in putting a computer to use
for considerable periods just for music playback is also
quite considerable as is wear and tear to the hardisks.
Reasons why the QA-350 is a better
music transport than a PC...
- Silent (no moving parts)
- No pops stutters or audio glitches
(assuming that WAVs were extracted with love by EAC)
- Uses nowhere near the amount of
energy that a PC needs
- Far more compact than even the
smallest laptop PC
- Useful remote control functionality