Luxman DA-250 User manual

Owner`s Manual
USB D/A CONVERTER
DA-250

USB D/A CONVERTER DA-250
Contents
Precautions ············································································································· 1
Features of This Unit································································································ 3
Names and Functions······························································································ 5
Connections ·········································································································· 15
Operations············································································································· 18
Block Diagram······································································································· 20
Specifications ········································································································ 21
Before Asking for Repair Services·········································································· 23

1
Precautions
Installation place
• Choose a stable place near the devices that are to be
used in combination with this unit.
• Do not install this unit near a television or color monitor.
Keep this unit away from such devices as cassette decks
that are susceptible to magnetic.
Avoid the following locations for
installation.
• Locations exposed to direct sunlight
• Places subject to humidity and with less ventilation
• Places where it is extremely hot or cold
• Places subject to strong vibration
• Places subject to dust
• Places subject to oil, steam, and heat (such as kitchens)
To avoid heat emission
Do not place this unit on such device as an amplifier that
may emit heat. If the unit is installed on a rack, install the unit
as distantly as possible from where the amplifier is installed
so as to avoid heat emission from the amplifier and other
audio devices.
Turn off this unit when it is not used.
Depending on the condition of radio waves emitted during
television broadcasting, interference fringes may appear on
the television monitor, but that is not a malfunction. In such
a case, turn off the unit. There may also be a case where
noises are heard on the radio due to radio wave interfer-
ence.
Notice when handling optical digital cables
• Do not fold the cables. For storage, wind each cable to
make a coil whose diameter is approx.15 cm or larger.
• For connection, insert the cable connectors firmly into the
terminals of this unit and the other device.
• Use the cables whose each length is 3 m or less.
• When the cable connectors get dusty, wipe the dust
away with a dry soft cloth before inserting into the termi-
nals.
Batteries
Caution:
Batteries used for remote controller shall not be exposed to
excessive heat such as sunshine, fire or the like.
Safety caution: Lithium battery
Warning Caution
• Put the lithium battery out of baby's reach.
• In case that the battery is swallowed, consult a doctor im-
mediately.
• Do not disassemble, throw in a fire, recharge, heat, solder,
or short-circuit the battery.
• Do not use or leave the battery in a hot place such as un-
der strong direct sunlight, in a car under the blazing sun,
and in front of a heater. Failure to observe this may cause
battery liquid leakage, heat generation, rupture, or ignition.
This may also degrade the performance or shorten the life
of the battery.
• Danger of explosion if battery is incorrectly replaced.
• Replace only with the same or equivalent type.
• If the battery is not used for a long time (1 month or more),
the battery shall be removed from the case to prevent bat-
tery liquid leakage. If the liquid leaks from the battery, wipe
the liquid off inside the case completely and load a new
lithium battery.
• To discard a used lithium battery, follow the instructions of
each local authority.

USB D/A CONVERTER DA-250
2
Cleaning
• Usually, wipe the unit with a dry soft cloth. When the dirt
is hard to remove, dip soft cloth in detergent diluted 5 or
6 times with water, wring it well, and remove contami-
nants. Then, remove the moisture with dry cloth.
• Do not use a solvent like alcohol, benzine, thinner, or
pesticide because such a substance can damage the ex-
terior. In addition, do not let this unit contact a rubber or
plastic form for a long time. That may damage the cabi-
net surface of the unit.
• When using a chemical cloth for cleaning, read the cau-
tion provided with the chemical cloth product.
• Before cleaning, unplug the power cord from the AC out-
let.
Precautions in connecting with other
components
When connecting this unit to input/output devices other
than a PC/Mac such as a CD player, an SACD player, a
DVD player, a tuner, and a power amplifier, be sure to turn
off the power of this unit and all other connected devices.
Failure to observe this may generate a strong noise resulting
in speaker damage or cause a malfunction.
The pin-plug to be inserted in each input terminal of this
unit shall be pushed in firmly. If the grounding terminal is
inadequately connected, noises including hum may be gen-
erated, resulting in an adverse S/N ratio.
Protection circuit
This unit is equipped with a protection circuit that is activat-
ed upon the detection of overcurrent to protect the head-
phones. When the protection circuit is activated, the output
to the headphones is shut off and the operation indicator
blinks to show that this unit is in the muting state. When
the cause to activate the protection circuit is eliminated, the
blue operation indicator light comes back on and the op-
erating state resumes. If the protection circuit is frequently
activated, please consult your dealer.
Insertion and extraction of headphone plug
When the headphone (unbalanced) plug is inserted or ex-
tracted, a short circuit occurs between the L ch output and
R ch output because of the structure of the headphone jack
(unbalanced).
If the volume of this unit is turned up at this moment, an
overcurrent flows to the headphone amplifier output and the
overcurrent detection circuit becomes activated, which sets
this unit to the muting state and may also cause a malfunc-
tion. Therefore, the insertion and extraction of the head-
phone plug shall be performed when the volume is turned
down to the minimum or when there is no signal after shut-
ting off input signals.
Repair and adjustment
When repairs or adjustments are needed, please ask the
dealer where you bought the unit.
Caution in using headphones
If the headphones are used for a long time at a high sound
volume level, your hearing may be damaged.

3
Features of This Unit
Compact chassis design
This unit is a D/A converter that has a compact body as
small as B4-paper size.
PCM1795 manufactured by Burr-Brown
For the DAC chip, this unit uses PCM1795 manufactured
by Burr-Brown that is used for the LUXMAN SACD player,
D-05u.
USB input supports 192 kHz / 32 bit
B-type USB input terminal is installed and makes it possible
to input USB digital audio signal from a PC/Mac.
The sampling frequency of up to 192 kHz and 32-bit quan-
tization are supported.
USB input supports DSD
DSD format data can be entered from PC/Mac, or the like.
Sampling frequencies of 2.8224 MHz/5.6448 MHz is sup-
ported.
Asynchronous communication supported
The USB input with low jitter has been achieved with USB
dedicated IC by asynchronous communication and PLL.
DD converter function
All the digital inputs including USB can be digitally output in
the S/PDIF format.
AD converter function
Analog line inputs can be converted into digital signals in
the S/PDIF format and output with coaxial or optical termi-
nal. Signals can be output as analog signals by the internal
DAC. (sampling frequency 96 kHz/24-bit)

USB D/A CONVERTER DA-250
4
LECUA (LUXMAN Electric Controlled
Ultimate Attenuator)
An electrically controlled attenuator LECUA, in which at-
tenuation is obtained by combining resistances, is used in
the headphone amplifier unit and analog output unit inde-
pendently to achieve fresh sound.
Built-in headphone amplifier
A high-grade headphone amplifier circuit with discrete cir-
cuit configuration is equipped. The output level can be se-
lected from 2 stages in accordance with the sensitivity of
headphones.
Built-in pre-amplifier circuit
A pre-amplifier circuit equipped with LECUA is embedded
in the analog output.
It is possible to connect the unbalanced or balanced out-
puts to the power amplifier and other directly, so that sound
volume can be controlled.
7-segment LED
The sampling frequency of the digital input and the select-
ed input can be displayed on the monitor with 7-segment
LEDs with a high level of visibility. The attenuation amount
is displayed during sound volume adjustment. The dimmer
function allows the brightness of the LEDs to be selected
from 4 levels.
Original technologies
Our traditional round pattern board, OFC internal wiring, and
original custom-made parts are fully and luxuriously used.
Remote control (RD-24)
Operations can be performed with a compact card-type
remote control.
*1 Mac and Mac OS are trademarks of Apple Inc., registered
in the U.S. and other countries.
*2 Windows is a registered trademark of Microsoft Corpora-
tion in the United States and/or other countries.
*3 DSD is a trademark.
*4 The described company names and product names are
trademarks or registered trademarks of each company.

5
Names and Functions
1. Operation switch (OPERATION)
This switch turns on and off the power.
When wiring or connection is performed, be sure to turn off
this switch.
2. Operation indicator (OPERATION)
Blinks in the time of muting mode when the operation
switch is turned on and lights up when the operation state
is activated afterward.
3. Input selector (INPUT)
Selects an input device connected to each input terminal.
Input transition goes as follows by clockwise rotation:
USB →COAX →OPT 1 →OPT 2 →LINE →USB ...
Input transition goes as follows by counterclockwise rotation:
USB →LINE →OPT 2 →OPT 1 →COAX →USB ...
Input: Digital output from a PC/Mac, a CD player,
an SACD player, a DVD player, and other such
devices (USB/COAX/OPT 1/OPT 2)
Analog line output from a CD player, an SACD
player, a tuner, a DVD player, a TV, and other such
devices (LINE)
4. Input selector display LED
Displays the input terminal selected with the input selector.
The input terminals are shown as follows:
USB input: USb
COAX input: COA
OPT 1 input: OP1
OPT 2 input: OP2
LINE input: LIn
5. Sampling frequency/volume level
display LED
(SAMPLING RATE/VOLUME)
Displays the sampling frequency of the digital signal con-
nected to the input terminal (USB/COAX/OPT 1/OPT 2)
selected with the input selector. When a digital input is
selected from USB/COAX/OPT 1/OPT 2 with the input se-
lector and the digital input signal from the digital device is
synchronized with this unit, the sampling frequency of the
digital signal is displayed on this LED.
When no digital signal is input or no synchronization is es-
tablished even with a digital signal input, the digital signal
unlock indicator lights up, and the sampling frequency is not
displayed on the LED.
When playback from a PC/Mac is stopped, the sampling
frequency disappears and the unlock indicator stays off.
This phenomenon indicates that communication with the
PC/Mac stays active.
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4
Front panel

USB D/A CONVERTER DA-250
6
This LED indicates the current volume level in steps of 1 dB
during sound volume adjustment.
• "- - -" shows the mute state. No sound is generated.
• The minimum volume level is shown as "–87 dB", and the
maximum volume level is shown as "0 dB".
The following sampling frequencies can be displayed.
Input from the USB
terminal
PCM : 32 kHz, 44.1 kHz, 48 kHz,
88.2kHz, 96 kHz, 176.4 kHz,
192 kHz
DSD : 2.8224 MHz, 5.6448 MHz
Input from OPT/
COAX terminals
: 32 kHz, 44.1 kHz, 48 kHz,
88.2 kHz, 96 kHz, 176.4 kHz,
192 kHz
First 3 digits are displayed on the LED.
6. Phase invert indicator (PHASE INVERT)
Lights up when the analog output phase is inverted by
pressing the phase invert changeover switch (PHASE) on
the remote control.
The following shows balanced output phases:
When the [Light is off]
1. GROUND
2. COLD (–)
3. HOT (+)
When the [Light is on]
1. GROUND
2. HOT (+)
3. COLD (–)
Both the unbalanced output and headphone output are in-
verted.
7. Headphone terminal sensitivity
indicator (SENSITIVITY HIGH)
Lights up when the headphone terminal sensitivity selection
switch (SENS.) is set to HIGH.
When the [Light is off]
NORMAL: Sensitivity setting 0 dB
When the [Light is on]
HIGH: Sensitivity setting +9 dB
8. Remote control infrared receiver (R)
Receives signals from the accessory remote control.
9. Digital signal unlock indicator
(UNLOCK)
Lights up when a digital input is selected from USB/COAX/
OPT 1/OPT 2 with the input selector and the digital input
signal from the digital device is not synchronized with this
unit.
10. Analog output level fix indicator (FIX)
Lights up when the analog output level fix/variable selection
switch (FIX/VARIABLE) on the rear panel is set to FIX.
At this moment, the volume control cannot adjust the ana-
log output level. (The sound volume of the headphones can
be adjusted regardless of the status of the selection switch.)
11. Volume control (VOLUME)
Adjusts the sound volume of the headphones, and the
sound volume of the device connected to the analog un-
balanced output terminals (RCA) or balanced output termi-
nals (XLR) when the analog output level fix/variable selection
switch (FIX/VARIABLE) on the rear panel is set to VARI-
ABLE. Sound is not generated when this control is rotated
counterclockwise to the end, and then, the sound volume
gradually becomes higher when the control is slowly rotated
clockwise.
When the analog output level fix/variable selection switch
(FIX/VARIABLE) on the rear panel is set to FIX, the analog
output level is not changed even if the volume control is
rotated.
12. Headphone jack (PHONES)
When listening to the playback sound of this unit with ste-
reo headphones, insert the headphone standard plug in this
output jack.
If the plug of your headphones is mini, use a mini-to-stan-
dard adapter that comes with the headphones or available
on the market.
The phase can be changed with the analog output phase
selection switch (PHASE) on the remote control.
DA-250 FIX/VARIABLE setting table
Output
Setting
Headphone
output
Analog output Digital output
RCA/XLR OPT/COAX
FIX Variable Fixed ○(Fixed)
VARIABLE Variable Variable ○(Fixed)

7
Names and Functions
13. Analog balance output terminals (XLR)
XLR connector terminal to output balanced playback sig-
nals from this unit.
The phase can be changed with the analog output phase
selection switch (PHASE) on the remote control.
The following are the phases of the output terminals of this
unit:
Normal 1. GROUND
2. COLD (–)
3. HOT (+)
Invert 1. GROUND
2. HOT (+)
3. COLD (–)
When the analog output level fix/variable selection switch
(FIX/VARIABLE) is set to VARIABLE, the output level varies
depending on the state of the volume control (VOLUME) on
the front panel.
14. Analog unbalance output terminals
(RCA)
RCA terminal to output unbalanced playback signals from
this unit.
The phase can be changed with the analog output phase
selection switch (PHASE) on the remote control.
When the analog output level fix/variable selection switch
(FIX/VARIABLE) is set to VARIABLE, the output level varies
depending on the state of the volume control (VOLUME) on
the front panel.
15. Analog output level fix/variable
selection switch (FIX/VARIABLE)
Sets the level of the playback signals from the analog output
terminal to FIX or VARIABLE.
When this switch is set to FIX, the analog output level fix
indicator (FIX) lights up to indicate that the output level from
the analog output terminal (RCA, XLR) is fixed and cannot
be adjusted with the volume control.
When the switch is set to VARIABLE, the output level of the
analog output terminal (RCA, XLR) can be adjusted with the
the volume control on the front panel or the remote control.
The sound volume of the headphones can be adjusted re-
gardless of the status of the selection switch.
When the selection switch is switched, the output level
may change greatly.
Be careful of the sudden change of the sound volume.
Rear panel
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