L-550AXII
INTEGRATED AMPLIFIER
L-550AXII
Owner`s Manual
Contents
Precautions ············································································································· 1
Features of This Unit ································································································ 2
Names and Functions ······························································································ 4
Connections ·········································································································· 12
Operations ············································································································· 16
How to use Remote Control ·················································································· 18
Block Diagram ······································································································· 20
Specifications ········································································································ 21
Before Asking for Repair Services ·········································································· 22
INTEGRATED AMPLIFIER L-550AX
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Precautions
Installation place
This unit shall be installed in a well-ventilated and effectively
heat-released place because this unit is an A-class amplifier
and generates considerable heat.
Especially, installation of this unit where direct sunlight is
present, where the temperature rises excessively high such
as close to a heater, or where it is humid or dusty may cause
a malfunction even if heat is efficiently released. Therefore, do
not install this unit in such places.
Ventilation holes
The ventilation holes on the top and bottom boards of this
product must not be blocked because this unit is an A-class
amplifier and generates considerable heat. If the amplifier is
installed on a rack or the like, secure ample space for cooling
and leave the door open. Do not pile up other things on the
amplifier and never put articles on it. Failure to observe this
may cause a malfunction.
Note:
For heat dispersal, do not install this equipment in a confined
space such as a book case or similar unit.
* Note
* *
*
Wall
Cautions in connecting speakers
When making speaker system connections, exercise extra
care not to short-circuit between ! and @ of the speaker
terminals and speaker input terminals of this unit.
If a large signal is applied to the amplifier with its circuit left
short-circuited, a large current may be passed through the
output circuit and cause a malfunction.
The sound is not generated shortly after
the power supply is turned on.
This amplifier is equipped with a time muting circuit in order
to separate the output circuit. Therefore, no sound will be
generated shortly after the power supply is turned on.
If the volume control is set to a high sound level before the
time muting circuit is canceled, a large sound is suddenly
generated. Please be advised that the volume control shall be
set to a low level at first and adjusted after the sound comes
out of the speakers.
Protection circuit
This product is equipped with a protection circuit that is ac-
tivated upon detection of overcurrent, abnormally high tem-
perature, and DC drift to protect the amplifier and speakers.
When the protection circuit is activated, the output to the
speaker terminal is shut off and the standby indicator blinks
to show that this unit is in the muting state. If the protection
circuit is frequently activated even when disconnecting the
AC plug from the wall outlet, waiting for a certain time, con-
necting the plug to the wall outlet again, and turning on the
power again, please consult your dealer.
Precautions in connecting with other
components
When connecting this unit to input devices such as a CD play-
er, an SACD player, a D/A converter, a tuner, and a recorder,
be sure to turn off the power of this unit and all other con-
nected 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 inade-
quately connected, noises including hum may be generated,
resulting in an adverse S/N ratio.
Batteries
Caution: Batteries used for the remote control shall not be
exposed to excessive heat such as sunshine, fire or the like.
Repair and adjustment
When repairs or adjustments are needed, please ask the
dealer where you bought the unit.
Cleaning
For cleaning, use a piece of soft cloth to wipe the unit such as
cleaning cloth. When the dirt is hard to remove, use a small
amount of neutral detergent to wipe, and then wipe the unit
with dry cloth. Do not use a solvent like benzine or thinner
because such a substance can damage the exterior.
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Features of This Unit
New LECUA1000 — LUXMAN Electric
Controlled Ultimate Attenuator 1000
New LECUA1000, which is the integration of an amplifier cir-
cuit and a high-precision attenuator by electrically-controlled
fixed resistance switcheovers is mounted. Further fine sound
volume adjustable without deterioration of sound quality from
0 dB through −87 dB
ODNF — Only Distortion Negative
Feedback —
The amplification feedback circuit that has acquired the high-
speed primary slew rate and ultra-wide bandwidth by feeding
back only distortion components generated during amplifica-
tion to maintain the pure sound quality of the main-amplifier
that is almost non-feedback.
The newest version, 4.0, has achieved the low impedance
and high S/N ratio of the transmission circuit thanks to paral-
lelized first stage and Darlington-connected second stage of
the amplification circuit. In addition, the input stages of the er-
ror detection circuit are parallelized to moderate the distortion
characteristic and to eliminate noise.
Parallel push-pull output stages
Parallel push-pull structure of bipolar transistors.
Pure class A rated output 20 W+20 W (8Ω).
High-inertia power supply
High-inertia power supply circuit that combines a large-ca-
pacity EI-core-type power transformer with original 10,000 μF
× 4 capacitor blocks.
Parallel speaker relays
This unit is equipped with 2 large parallel speaker relays with
a low resistance value to reduce the impedance of the speak-
er output lines.
Beeline construction
Newly designed beeline construction makes the audio input
signals to be conveyed via the optimum and shortest route to
the speaker output.
Selector switch IC
Selector switch IC of high sound quality, which is used in the
top-end control amplifier, C-900u, improves the separation
and crosstalk performances.
Schottky barrier diode
Application of Schottky barrier diode manufactured by Nihon
Inter Electronics Corporation that has less switching noises
and higher conversion efficiency to the DC voltage for the
power supply rectifier circuit.
LUXMAN’s original OFC wires
Our original OFC wires are used in the internal wiring to
achieve smooth signal transmission thanks to the spiral wrap
shielding on each core and the non-plating process on the
core wire.
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INTEGRATED AMPLIFIER L-550AX
Ⅱ
Round pattern board
After careful consideration of delicate audio signal flow, a
round pattern board has been applied to achieve smooth sig-
nal transmission.
Phono amplifier
This unit is equipped with a phono amplifier that is compat-
ible with the MM/MC cartridge to achieve analog record re-
production in a high-grade level without adding a dedicated
phono amplifier.
Separate function
This unit is equipped with a separate switch to separate the
pre-amplifier and power-amplifier each other that enables the
bi-amp connection adding a power-amplifier and the coexis-
tence with an AV system.
Loopless chassis structure
This unit consists of the independent construction of a
loopless chassis to eliminate increased ground impedance
caused by chassis current.
Large type speaker terminals
Speaker terminals (A and B systems) of inline layout (with
same characteristics for right and left), which is compatible
with Y lugs to enable easy connection with extra-thick speak-
er cables.
Headphone output terminal
This terminal allows you to casually enjoy sound with head-
phones.
Needle-type meter
This unit is equipped with needle-type meters lighted with
LED, which improves the visibility in the listening room.
Aluminum remote control
The high-grade remote control, which is encased in alumi-
num, can control applicable CD/SACD players as well.
18 mm pitch RCA terminal
Introduction of 18 mm pitch all RCA input/output terminals
allows even a high-performance line cable with large plug to
be connected.
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Names and Functions
891011121314151617
5 6 7
1 2 43
Front panel
1. Operation switch (OPERATION)
2. Operation indicator (OPERATION)
Toggles the power on and off. When wiring or connection is
performed, be sure to turn off this switch.
Blinks in the time of muting mode when the operation
switch is turned on and lights up when the operation state
is activated afterward. This indicator blinks when the unit is
in the muting mode or when the volume is adjusted with the
remote control.
3. Input selector (INPUT SELECTOR)
Selects an input device from the devices such as a CD play-
er, an SACD player, a D/A converter, and a tuner connected
to each input terminal.
The input selector has 6 positions consisting of LINE-4,
LINE-3, LINE-2, LINE-1, BAL LINE, and PHONO from left
to right that correspond to each input terminal on the rear
panel. Rotate the knob to light the input indicator of the
input device to be selected.
4. Input indicator
Lights up at the input device selected with the input selector
or remote control.
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INTEGRATED AMPLIFIER L-550AX
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5. Display window
Displays the operation status of this unit.
This window is composed of 7 indicators and 2 power me-
ters.
6. Remote sensor (REMOTE)
Receives signals from the accessory remote control.
7. Volume control (VOLUME CONTROL)
Adjusts the sound volume. 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 rotated clockwise as follows: mute → –87 dB →
–86 dB → ...... → 0 dB in steps of 1 dB.
8. Headphone jack (PHONES)
Insert the headphone plug into this output jack. Even when
the plug is inserted, signals to the speaker output terminal
are not interrupted. Accordingly, to listen to sound with only
use of headphones, set the speaker selector to “OFF”.
9. Separate switch (SEPARATE)
Separates the pre-amplifier and main-amplifier each other.
off (separate indicator off):
Uses this unit as a normal integrated amplifier.
on (separate indicator on):
Feeds external signals from the MAIN IN terminal on
the rear panel to the main-amplifier section.
• This switch toggles the separate on and off.
The separate indicator lights up when the separate switch
is on.
When the separate switch is set to on, the volume control
of this unit cannot adjust the volume of the speakers con-
nected to this unit. Volume adjustment shall be performed
at the input device side such as a control amplifier con-
nected to the MAIN IN terminal.
Entry of direct output into the MAIN IN terminal from a CD
player or other devices that cannot adjust sound volume
always provides full power and accordingly there is a risk
of speaker damage.
For such input devices, be sure to use a control amplifier
equipped with the sound volume adjustment function as a
relay, generate sound through the speakers with volume
lowered, and adjust the volume to your favorite level.
When arranging the wiring, be sure to turn off the power
of this unit.
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Names and Functions
891011121314151617
5 6 7
1 2 43
Front panel
10. Line straight switch (LINE STRAIGHT)
Enhances the purity of the sound quality by bypassing the
balance control circuit, tone control circuit, or the like.
off (line straight indicator off): Line straight off/bypass off
on (line straight indicator on): Line straight on/bypass on
• This switch toggles the line straight on and off.
The line straight indicator lights up when the line straight
switch is set to on.
When the line straight switch is set to on, the balance con-
trol, tone control, subsonic, monaural and loudness cannot
be adjusted and the mode selector does not function.
11. Balance control (BALANCE)
Adjusts the balance of sound volume between right and left
channels.
Rotating this control counterclockwise makes the left sound
volume enhanced, and rotating the switch clockwise makes
the right sound volume enhanced. This control shall be set
to the center position under normal conditions, and rotated
to make adjustment if necessary.
When the line straight switch is set to on, this switch does
not function.
12. Tone control for treble
TONE CONTROL (TREBLE)
Controls the frequency characteristics of the high-frequen-
cy range.
When this control is set to the center position, flat frequency
characteristic is obtained. Rotating this control clockwise
makes the high-frequency range enhanced, and rotating
this control counterclockwise makes the high-frequency
range attenuated.
When the line straight switch is set to on, this switch does
not function.
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INTEGRATED AMPLIFIER L-550AX
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13. Tone control for bass
TONE CONTROL (BASS)
Controls the frequency characteristics of the low-frequency
range.
When this control is set to the center position, flat frequency
characteristic is obtained. Rotating this control clockwise
causes the low-frequency range to be enhanced, and rotat-
ing this control counterclockwise causes the low-frequency
range to be attenuated.
When the line straight switch is set to on, this switch does
not function.
14. Speaker selector (SPEAKERS)
Selects either of 2 speaker systems, A or B, located at the
rear panel.
OFF: Set to off when using headphones. No sound is
generated from any speakers.
A (center): Selects the A system speaker terminals.
B: Selects the B system speaker terminals.
A+B: Simultaneously activates both A and B system
speakers. When both speaker terminals are si-
multaneously used, select speakers with imped-
ance of 8 ohms or more because both output
terminals are connected in parallel.
15. Recording switch (REC OUT)
Sends recording signals to the recorder connected to this
unit.
OFF: Does not send recording signals to the record-
er output terminals on the rear panel.
When not using the recorder, set the recording
switch to OFF.
ON: Selects an input source to be recorded with
the input selector and sends recording signals
to the recorder connected the recorder output
terminals of this unit.
16. Cartridge selection switch
(CARTRIDGE)
Changes the gain level of the equalizer amplifier (amplifier
circuit required to play an analog record).
MC: Selects the MC (moving coil) type cartridge of
low output voltage.
When “MC” is selected during use of the MM
type cartridge, be aware that the sound volume
becomes higher and unbalanced sound without
high frequencies is generated owing to the im-
pedance.
MM: Selects the MM (moving magnet) type cartridge
of high output voltage.
17. Monitor switch (MONITOR)
Toggles between use and nonuse of the monitor input ter-
minals (MONITOR) on the rear panel.
on (monitor indicator on):
Enables to reproduce the data from the recorder.
off (monitor indicator off):
Enables to reproduce the signals from the source se-
lected with the input selector.
• This switch toggles the monitor on and off.
The monitor indicator lights up when the monitor switch
is on.
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