COS D2 User manual

Thank you for choosing D2/D2V.
Please have a few minutes for this manual before powering D2/D2V on.
In what follows, D2 refers to both D2 and D2V, but anything related to
volume is applicable to D2V only.
WELCOME

Getting Started
Unpacking
Placement
Connection
Mains Connection
Input
Analog Output
Buffer Selection
USB Audio Selection
Operation
Powering On And Off
Selecting Input Source
Adjusting Volume Level
Standby Mode
Remote Control
Display
Tips for Optimum Performance
Specification
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You will find in the D2 box the following:
• COS D2
• a remote control (D2V only)
• this manual
Please keep the D2 box. In an unlikely event that maintenance is needed,
the box shall be used for protection of D2 in transit.
UNPACKING
Getting Started
PLACEMENT
D2 needs a solid and stable surface to stand firmly, and four boots should
help keep it level. D2 does not need much air to stay operational, but
suffocating it is certainly a bad idea. Where D2 is placed is not critical,
but please keep it away from known magnetic fields.
1
CONTENTS

#1 USB Audio (USB Type B connector)
D2 supports both USB Audio Class 1.0 and 2.0 with the following
sampling rates and bit depths:
• Audio Class 1.0 - up to 96K samples per second, 16/24 bits depth
• Audio Class 2.0 - up to 192K samples per second, 16/24 bits
depth and DSD64/DSD128 (DoP)
#2/#3 Optical Input (Toslink)
#4 S/PDIF Input (RCA connector)
#5 AES/SBU Input (XRL female connector pair)
Pin 1: Ground
Pin 2: Signal + (non-inverting)
Pin 3: Singal - (inverting)
Connector ground lug: chassis ground
There is a buffer switch on the back panel, and it should be turned on for
optimum performance. Sometimes digital music data do not move along
and get converted in perfect tandem, which causes jitters, and even a
few micro-seconds timing error is enough to perturb the ears and frustrate
the mind. Therefore, D2 uses a buffer of one-second depth, along with an
independent and accurate clock, to receive data, align them and send
them out in precise time frames for conversion.
For videos, the buffer should be switched off. This selection makes
D2 reduce the depth of the buffer a little to ensure video-audio
synchronization. Switching the buffer on or off takes effect immediately.
3
BUFFER SELECTION
Connection
2
INPUT
Connection
1. Unbalanced analog output: RCA
2. Balanced analog output: XLR male
The pin assignments of these XLR-type male outputs are:
Pin 1: Ground
Pin 2: Signal + (non-inverting)
Pin 3: Singal - (inverting)
Connector ground lug: chassis ground
ANALOG OUTPUTMAINS CONNECTION
D2 works from 100 to 240VAC mains, so voltage selection is not needed.
Please set D2 into standby mode and use the USB AUDIO switch
on the back panel to make your selection. The selected class
takes effect when D2 leaves standby mode. Both Audio Class 1.0
and 2.0 work on MAC OS, but only Class 1.0 works on Windows.
They are natively supported; there is no need for additional device
drivers.**

After power is switched on, the COS logo will appear on the display for a
few seconds, and the working status such as input source will be shown
afterwards. Now D2 is successfully powered on and ready for input
source selection.
The default input source is USB 1.0 or 2.0 depending on your selection
from the back panel, and the next input source can be selected by shortly
pressing the knob. The order of the selection is USB 1.0 (or 2.0), Optical,
RCA, XLR, and back to the USB 1.0 (or 2.0) as a loop.
SELECTING INPUT SOURCE
D2 supports both USB Audio Class 1.0 and 2.0. The main difference
between USB Audio Class 1.0 and 2.0 is that the USB Audio Class 1.0
can’t go beyond 96K samples per second with 24 bit data depth.
Always power D2 off or put D2 into standby mode before adjusting
the USB Audio Selection switch. The selection takes effect when D2 is
powered on or leaves standby mode.
5
Operation
4
USB AUDIO SELECTION
Connection
Volume is changed by rotating the knob. Rotating the knob
counterclockwise brings the volume up; clockwise, down. And it is shown
on the display from -63.75dB to 0dB (loudest) with a 0.25dB interval.
ADJUSTING VOLUME LEVEL
POWERING ON AND OFF
A long press (about one second) on the knob or a press on the STANDBY
key on the D2 remote control puts D2 into standby mode. In this mode,
the volume and output relays are turned off, and D2 goes into a state of
low power consumption. Another long press on the knob or a press on
the STANDBY key on the remote control makes D2 leave standby mode;
music resumes and volume hops back to the previous level.
STANDBY MODE
The D2 remote control is easy to use. Just aim the remote control at D2
and press buttons. When power is running low, please use a screwdriver
to open the cover at the back of remote control to replace batteries.
REMOTE CONTROL

6
Operation
STANDBY MODE
7
A 128 by 64 pixels white OLED display is used to show the current status.
DISPLAY
Volume shown on the upper portion
Buffer Input Source
Music Status
(Solid: Play
Blinking: Mute)
D2
Buffer Input Source
Music Status
(Solid: Play
Blinking: Mute)
D2V
Operation
• Give D2 ten minutes to warm up and attain an internal thermal
equilibrium, which ensures a seamless flow of enchanting music.
• Switch the one-second buffer on for music and off for video.
• Turn off the up-sampling feature of your player and play music at its
original sampling rate. D2's dedicated DSP with COS Engineering's
algorithms will do a the job.
• Fix the volume of your player at its maximum and use D2 to adjust
volume. Failing to do so may reduce the bit-depth of music data and
compromise musicality.
** If you are a Windows user and interested in using Audio Class 2.0 for D2, please visit
www.cosengineering.com. Driver and more information are available.
TIPS for OPTIMUM PERFORMANCE

Specification
SPECIFICATIONS
DAC
Steps 256 steps by 0.25dB/step
Total Range 64dB
Accuracy Within + 0.1dB
Digital Inputs USB x1, Asynchronous 1.0/2.0;
SPDIF x 1; TosLink x 2; AES x 1
Sampling Rate
TosLink x 2; AES x1
Optical / RCA / XLR: up to 192K PCM
24 bits & DSD64 (DoP)
USB 1.0 – up to 96K PCM 24 bits
USB 2.0 - up to 384K PCM 24 bits &
DSD64/DSD128 (DoP)
Digital-to-Analog Converter 24-bit DAC x 2
(up to 192Ksps, 24-bit)
Digital Filter COS Proprietary
Linear Phase Delay
Specification
SPECIFICATIONS
Analog Output
Frequency Reponse + 0dB, - 0.5dB (20Hz ~ 20KHz)
THD+N
< 0.001% (- 100dB)
(192Ksps, 24-bit, 20Hz ~ 20KHz,
A-weighted, 16 ohm load, 2Vrms)
Signal-to-Noise Ratio
>110dB
(192Ksps, 24-bit, 20Hz ~ 20KHz,
A-weighted, 16 ohm load, 2Vrms)
Output Impedance 100 ohm
Full Scale Output Unbalanced: 2Vrms
Balanced: 4Vrms
General
Disply 128 x 64 pixels white OLED
Weight 3.5 Kg
Dimension 260 mm (W) x 250 mm (D) x 60 mm (H)
(boot is not included)
Power
100 ~ 240VAC
Normal Operation < 15W
Standby 0.5W (typical)