|
 |
 |
|
|
Quloos QU02 USB Bridge
USB Digital Audio Interface to SPDIF
AES/EBU I2S |
|
 |
 |
| Amanero Combo384 |
|
|
 |
| Supporting DSD512 |
|
|
|
 |
|
A full isolation to
isolate PC EMI |
|
|
|
 |
| Both ends of isolation
are powered by local |
|
|
 |
| Generating I2S signal by
CPLD |
|
|
 |
| Using Hi-End special
oscillator AS338 |
|
|
|
 |
| Using multiple Linear
power chips |
|
|
 |
| Four kinds of cable
sequences of I2S |
|
|
|
 |
|
Can of driving Length=10m
coaxial cable |
|
|
|
 |
| For optimization of car
audio system |
|
|
 |
| Can be powered by 12V
battery power supply |
|
|
|
 |
|
Supporting multi-platform
operating system |
|
|
| |
|
What’s the USB Bridge? |
● For QU02, It is a digital audio converter for USB convert
to coaxial, optical, AES/EBU, I2S (IIS) digital audio
output.● Briefly speaking, USB Bridge can also be deemed as an
external high-quality digital sound card that can connect to
mobile phones, computers and tablets.
● The purpose of USB Bridge is to improve the sound quality
of DAC, so that the sound quality of DAC connected to
computers, mobile phones and tablets can reach or even
exceed that of many digital players.
|
|
How to use? |
It’s simple. QU02 can be connected to computers, mobile
phones and tablets (mobile phones and tablets need an
OTG converter to convert to USB-A port) through USB
cable, and then output connect to DAC, active speakers
with digital audio input, power amplifiers with digital
audio input, and DSP of car audio through digital audio
cable. The methods of connecting backend devices include
coaxial, optical, AES and I2S.
|
 |
|
|
Why to design QU02?
|
● [Replaceable sound quality/exceeding many digital
players] Whether we are designing the QA661, or the
designing the a better sound quality QA662, we reached
a conclusion that as long as the USB Bridge was
excellent enough, the sound quality was replaceable or
even exceeded many digital players.
● [Playing online streaming music easily] There is a
certain threshold for using online players, which
increased user’s difficulty on using them, especially if
they wanted to use them well. However, there is almost
zero threshold when using USB Bridge to listen online
streaming music. No matter is mobile phones, tablets or
computers, it’s easy to play online streaming music.
● [The best choice to improve the sound quality] For
most DAC, or HiFi devices with DAC, the simplest and
most effective way to improve the sound quality is to
add an excellent USB Bridge in front of it, with small
investment, but realizing a significantly improved sound
quality.
|
| |
|
New Isolation Technology |
When both ends of
the isolation are powered by the local pure power supply, we
can hear the sound that is smoother, with cleaner background
and more details.
|
|
 |
● To effectively eliminate the ground loop noise
introduced from the computer, the standard USB Bridge
are equipped with complete ground isolation, such as
INT204, Hydra Z+, Alpha, A.B.C, as well as some
excellent USB Bridge in China. It’s obvious that a lot
of efforts have been accumulated in this aspect.● The isolation design of QU02 is also unique. The CPU
part of the USB Bridge, the audio output processing part
and the clock part are completely isolated. The purpose
is to isolate the interference caused by the computer,
so that the sound is more pure and accurate.
● However, for almost all similar designs that adopted
complete isolation, partial power supply of CPU of USB
Bridge is by 5V power supply from USB inputted, so the
sound will be greatly influenced by 5V power supply from
USB inputted.
● How about QU02? It directly abandoned 5V power supply
from USB inputted and uses local pure power supply at
both ends of isolation.
Because both ends are designed with complete isolation, we
made the isolation up to 3000 V DC voltage before and
after isolation, through Murata isolation power module.
Through isolating the power supply, we realized the
couplings, which not only realizes the complete
isolation, but also ensures that both ends are supplied
with pure power supply with low internal resistance.
|
| |
|
Clock circuit design regardless of the cost
--- Clock is the Soul of Sound |
A lower clock jitter can realize a better sound quality and significantly improve the medium frequency and low frequency quality that human ear is more sensitive. Make sound has toughness, the instrument and voice have a touchable real object sense. In addition, the low jitter makes the high frequency more delicate, exquisite and accurate. |
|
 |
● QU02 selects wurth’s high-precision crystal oscillator
for partial CPU of USB, because a poor CPU clock will
bring a large EMI interference to power supply and
surrounding space. The stability of Wurth crystal
oscillator and low jitter will make the position of
sound image more accurate, more three-dimensional
effect, and more open sound scene.● The audio of QU02 uses two AS338 crystal oscillators
(Accusalicon specifically launched for Hi-End audio
applications). This crystal oscillator, with selling
price more than US $50/pc, is a more high-end model of
popular AS318B in Hi-Fi applications, whose phase noise
and jitter performance are leading the similar products.
|
|
|
|
|
|
 |
vs |
 |
|
AS338 Jitter
38fs |
|
AS318 Jitter
88fs |
| |
|
|
|
|
vs |
 |
|
AS338 10Hz phase noise
-109.5dBc/Hz |
|
CCHD-957 10Hz phase noise
-100dBc/Hz |
|
|
|
● The jitter of AS338 is as low as 38fs, much lower than
the 88fs of AS318B. The 10Hz phase noise, which has a great
influence on hearing, is lower than the popular crystal
oscillator CCHD-957 by about 10dB. |
| |
|
Excellent
Jitter With Coaxial Output |
|
|
|
 |
The above jitter test diagram is for
QU02 engineering machine. About test screenshot under
APX555 instrument, our parameters are marked as 80ps,
because there will be some deviations on parameters of
each machine.
|
Through applying low noise and pure power supply to
power AS338 crystal oscillator, excellent digital signal
processing circuit and excellent CPLD frequency division
design, we successfully realized the incredible low
jitter audio output.There is only 80ps with coaxial
output jitter, which is only 40% of jitter 200ps of many
single digital audio processing chips.
|
| |
|
Coaxial Output THD and SINAD |
|
|
|
 |
| |
|
Power supply is the source of sound, Taking the largest part of cost |
|
|
|
|
|
|
● The biggest cost gap between different devices generally lies in power circuit. For example, in terms of price, many Linear power chips are 10-20 times than that of general power chips.
● In addition, for most machine designed, there only needs a few power chips. However, we will use over 10 or even dozens of power supply chips, which caused a huge cost gap. We will divide the power supply into several groups according to the major categories (including high-frequency and low-frequency, audio and non-audio). Then, during the second stage, we will divide into several groups according to different current sizes and different interference levels. Finally, during the third stage, we will supply power to each specific electric circuit independently. The advantage is that we realized countless independent power supply effects inside a machine, ensuring the independence of each other, isolating their influences, and ensuring the purity, refinement and accuracy of sound.
● There are two main reasons that explains why Linear’s power chip is expensive. On the one hand, the parameters are excellent, rare low noise, and fast enough transient response. On the other hand, the actual performance of the sound is good. The sound of the linear power supply chip is exquisite and has many sound details. Compared with the conventional power supply chips, it is significantly improved.
|
|
 |
VS |
 |
VS |
 |
|
LT3042 Noise:
0.8uV |
|
ADP151 Noise:
9uV |
|
LM7805 Noise:
75uV |
|
| |
● How excellent are the parameters of Linear power chip? Let's just take a brief look at the noise index. The noise of LT3042 is 0.8uV, which is only 8% of the 9uV noise of the commonly used low-noise power supply chip ADP151, and only 1% of the 75uV noise of the regulator chip LM7805.
● The Linear power chip used by QU02 includes multiple LT3042, LT1963 and LT3693.
● To achieve excellent sound quality and actual hearing sense, QU02 uses not only complex power circuit design and expensive power chips, and also uses the Philips axial electrolytic capacitor, Philips 135 electrolytic capacitor, Philips 030 axial electrolytic capacitor, Murata power source isolation module, Murata common mode inductance, WIMA film capacitor, ERO film capacitor, Panasonic SMD film capacitor.
|
| |
|
A perfect sound for
Computer input and Mobile phone for input |
|
 |
● For most of the independent USB Bridge on sale now,
the power supply used in the circuit before isolation is
the 5V power supply from USB inputted, which determines
that the sound will inevitably be influenced by the
quality of USB inputted power supply. When connected to
a computer with a better power supply, the sound will be
better. However, when connected to a computer or mobile
phone with a bad power supply, the sound will be worse,
which is manifested in that the sound tends to become
hazy, thin, weaken details, unclean and lacking in
three-dimensional sense.
● Some user will try to add USB noise purifier to
solve this problem. However, although most USB noise
purifiers can bring a clean sound, but they also cause
the loss of sound details or make the sound thin, which
makes the original goal became impossible.
● Because QU02 used Murata power isolation module and
completely abandoned 5V power supply from USB inputted,
realizing that the sound is completely free from the
influence of power supply from USB inputted. The
advantage is that when the mobile phone is used as the
sound source, it will have better sound quality
performance than similar products. The difference
between the sound computer inputted and mobile phone
inputted has been narrowed. Adopting mobile phone as the
sound source can realize HiFi sound.
● An OTG conversion cable to USB-A port is needed, If
the QU02 is connected to Android or iPhone and tablets,
so as to realize a convenient online streaming music
playing and wonderful enjoyment of a high quality of
sound.
|
| |
|
It is can drive the coaxial cable with a length of 10M |
|
 |
● When we conduct the actual test with 75ohm Canare
coaxial cable in a length of 10m, there is almost no
influence to sound quality. When the length of coaxial
line is increased from 1.5m to 10m, the Jitter is only
increased from 72ps to 74ps, so that such a slight
difference can be ignored.
● If needing a longer distance, it is recommended to
use AES for connection. In theory, AES can support a
long distance transmission of 100m.
● Therefore, your computer and audio can be free from
each other.
|
|
|
|
User-Friendly
Audio Source of Car Audio |
|
|
|
|
|
|
● When using QU02, we find that not only
the coaxial cable can be a length of 10 meters, but also
the USB cable can be a length of 10 meters through our
actual measurement, which is very friendly to car audio
users.
● No matter you plan to install QU02 in
trunk of the car and use a long USB cable to connect the
phone and tablet to the dashboard, or you plan to
install QU02 under the seat and use a long coaxial cable
to connect to DSP input of car audio in rear boot, both
are achievable, which is more convenient and can
experience better sound quality of Hi-Fi on car audio.
● QU02 uses external 12V power input.
Since the maximum power supply of car can reach 14V, it
cannot be used directly. Therefore, we provide two
vehicle power supplies for car audio users to choose
(need to purchase separately). These two power supplies
are equipped with noise filtering function, and the
voltage will be stabilized to a fixed 11.5V to ensure
stable use and sound performance. One of the two vehicle
power supplies is the interface of the vehicle cigarette
lighter, which can be directly plugged into the vehicle
cigarette lighter. The other type of power input is
connected by terminal blocks, and ACC is provided as the
control input for power startup. (When purchasing the
vehicle power supply, please find it directly in the
store or kindly consult us)
|
|
|
|
|
|
|
|
Sample Rate Indicator |
| |
1X |
2X |
4X |
8X |
| 44.1kHz(PCM) |
44.1kHz |
88.2kHz |
176.4kHz |
352.8kHz |
| 48kHz(PCM) |
48kHz |
96kHz |
192kHz |
384kHz |
| DSD |
DSD64 |
DSD128 |
DSD256 |
DSD512 |
|
|
|
|
Supports
Multiple Port Output |
QU02 has I2S, AES, Optical, 2 Coaxial digital audio
signal output.
|
|
 |
|
Sample Rate Supported By The
Output Port |
| Port |
PCM |
DSD |
| I2S |
32Bit / 44.1kHz ~
384kHz |
DSD64 ~
DSD512(Native) |
| AES |
24Bit / 44.1kHz ~
384kHz |
Dop64 ~ Dop128 |
| OPT |
24Bit / 44.1kHz ~
192kHz |
Dop64 |
| COAX |
24Bit / 44.1kHz ~
384kHz |
Dop64 ~ Dop128 |
|
| |
|
Impedance and Level of The Output Port |
| Port |
Impedance Matching |
Output Level |
| I2S |
100Ω |
LVDS |
| AES |
110Ω |
3Vpp |
| OPT |
--- |
--- |
| COAX |
75Ω |
0.55Vpp |
|
|
|
Selectable I2S
Cable Sequence |
Four groups of switches can adjust four conventional I2S
cable sequences, so as to realize the compatibility with
DAC of different brands
|
 |
● K1: K1 to ON, DSD FLAG is PIN15, Set
PIN15 as the FLAG Bit.
● K2: K2 to ON, DSD FLAG is PIN14, Set
PIN14 as the FLAG Bit.
● K3: Phase setting of I2S interface,
K3 to ON is Standard phase,K3 to OFF is Reverse
phase.
● K4: DSD channel setting for I2S
interface, K4 to OFF is DSDR using LRCK，K4 to ON
is DSDR using DATA.
Note: After setting K3 or
K4, You need to restart the device for this to take
effect.
|
|
|
|
|
 |
Note: Cannot connect with
HDMI of computer, TV and set-top box
|
|
|
|
Local drawing of internal PCB
|
|
|
|
 |
|
|
Statement: The above
internal pictures and PCB plate pictures are for
reference only. To continuously improve the sound
quality and performance of product, materials or
circuits are subject to change without notice.
|
|
|
|
Other
Parameters |
● Input power: DC12V 2A (range: 11-13V, >500mA),
5.5 x 2.1mm, positive inside and negative outside
● Power consumption of whole machine: <5W
● Systems supported: Windows (ASIO driver), Mac,
Android, iOS, Linux (drive-free)
● Size of host: 197 x 197 x 45mm (Not including
exposed sockets and foot mats)
● Weight of host: 1.29kg
● Size of package: 330 x 260 x 75mm
● Weight of package: 1.72kg
● Package list: QU02 host, USB Cable(USB-A to B,
L=1.5M), Instruction Manual, DC12V 2A Power Supply
(Input AC110~240V)
|
|
|
|
Price: QU02 USB Bridge US $389.99 (Not included
shipping)
|
|
|
|
|
|
