Luxman MQ-88uSE User manual

Owner`s Manual
VACUUM TUBE STEREO POWER AMPLIFIER
MQ-88uSE

Contents
Precautions ············································································································· 1
Names and Functions······························································································ 2
Connections ············································································································ 4
Block Diagram········································································································· 6
Specifications ·········································································································· 7
Before Asking for Repair Services············································································ 8

VACUUM TUBE STEREO POWER AMPLIFIER MQ-88uSE
1
Precautions
Installation place
Install this unit in a location where good ventilation and heat
radiation is assured.
Do not install it where the temperature is high such as in
direct sunlight, or where it is dusty or humid, as this could
result in damage to this unit despite proper heat radiation.
Ventilation holes
The ventilation holes on the top and bottom boards of this
product must not be blocked because this unit is a vacuum
tube amplifier and generates considerable heat. If the am-
plifier 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 con-
fined space such as a book case or similar unit.
*Note
Wall
**
*
Precautions in connecting with other
components
When connecting this product to input devices such as a
control amplifier, be sure to turn off the power of this prod-
uct and all other connected devices. Otherwise, a very
strong noise may be generated and destroy the speakers.
In the worst case, this can cause equipment 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.
Cautions in connecting speakers
When making speaker system connections, be sure not to
cause short-circuiting between !and @of the speaker ter-
minals and speaker input terminals of this unit. If signals are
applied to the amplifier with its circuit left short-circuited, a
large current may be carried in the output circuit and cause
malfunctioning.
The sound is not generated shortly after
the power supply is turned on.
This product is a vacuum tube amplifier, and therefore, it
cannot deliver a sound until the vacuum tube heaters warm
up.
You can enjoy music 1 minute or more after turning on the
power. We therefore advise initially setting the volume con-
trol at a low level. After that, you may move the volume con-
trol to your favorite sound level after the initial sound comes
out of the speakers.
Repair and adjustment
When repairs and adjustments are needed, please consult
with 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.
Safety caution
Caution
This unit is a vacuum tube power amplifier. Be careful not to
touch this product with your bare hand because this product
becomes hot in the power-on state. For safety, do not use this
product in a place where children or unchained animals are
present.

2
Names and Functions
1. Power indicator (OPERATION)
Turns orange when the power is turned on.
2. Power switch (OPERATION)
Toggles the power on and off.
When wiring or connection is performed, be sure to turn off
this switch. When turning on the power switch again after
turning the unit off, wait for more than one minute.
When the power is turned off, the OPERATION indicator
will stay on for a while, but it is not a malfunction.
3. Volume control (VOLUME)
This function is effective only when a source component
such as a CD player is connected to the VARIABLE input of
this unit to adjust the input level.
When the connection is made with the direct input (DI-
RECT), the signals do not go through this volume thus the
sound volume does not change.
When the DIRECT input is connected, please take extra
care for the volume of the other connected unit.
321
Front panel

VACUUM TUBE STEREO POWER AMPLIFIER MQ-88uSE
3
4. Direct input terminals (DIRECT)
Connects to a control amplifier or a source component.
When connected to this input terminal, the signals do not
go through the volume circuit, thus rotating the volume con-
trol on the front panel will not change the volume.
5. Variable input terminals (VARIABLE)
Connects to a source component, e.g. a CD player without
output level control.
The sound volume can be adjusted by the volume control
of the front panel.
If using a control amplifier with high output impedance in
combination with this unit, use of the connection cable as
short as possible is recommended to avoid unnecessary
treble attenuation.
6. Input selector (VARIABLE/DIRECT)
Variable or direct input can be switched.
Select the name of the terminals connected to the device to
play back by operating this switch.
When switching the input, be sure to turn off the power.
If the power is on while switching, large noise might be
generated.
7. Speaker terminals (SPEAKERS)
Connects a speaker system.
The right speaker terminals shall be connected to the R
side, and the leftspeaker terminals shall be connected to
the L side in consideration of the polarity !and @.
The range of the impedance of the speaker to be connected
should be between 4 Ω and 16 Ω.
8. AC inlet (AC IN)
Connects the accessory power cable. The power shall be
supplied from a household wall socket.
84 5 6 7
Rear panel

4
Connections
CONTROL AMPLIFER
CD PLAYER
ANALOG PLAYER
RECORDER
CD/SACD PLAYER
CD PLAYER
CD/SACD PLAYER
L R
SPEAKER SYSTEM
–+ –+

VACUUM TUBE STEREO POWER AMPLIFIER MQ-88uSE
5
Before Connecting
Before connecting other devices, connect the jack side of
the accessory power cable to the AC inlet of this unit.
When connecting, turn off the power supply of this unit and
the power supplies of auxiliary devices to prevent unex-
pected accidents that may be caused by noise.
How to connect power supply
Use the accessory power cable and insert the AC plug in
the outlet on the wall in the room where the unit is installed.
How to connect CD player, control
amplifier
Connect the output terminal of a control amplifier to the in-
put terminal with 2 (R and L) pin-plug cables.
When using a source device without the volume adjusting
function, such as a CD player, connect to the VARIABLE
input terminal. When using a source device with the volume
control, such as a control amplifier, connect to the DIRECT
input terminal.
Select DIRECT or VARIABLE input with the input selector.
How to connect speakers
Connect the right-channel speaker to the right speaker ter-
minals of the MQ-88uSE power amplifier and the left-chan-
nel speaker to the left speaker terminals.
Securely connect the !terminal of the speaker system to
the speaker terminal !(red) of this unit, and the @terminal
of the speaker system to the speaker terminal @(black) of
this unit.
If the !and @terminal is reversely connected to either of
the right or left of the speaker system, the signal phases
reproduced from the right and left of the speaker system
are also reversed. In such a case, be aware that the sound
level in the low range will be reduced and the acoustic sta-
bility will worsen, thus the normal stereo playback is not
achieved.

6
Block Diagram
COMMON TP-V2 TP-V1
DIRECT VARIABLE
PARALLEL
6
OUT
+ –
CHOKE
SW
3.6K
ECC803S ECC802S KT88
KT88
KT88 KT88 KT88
ECC802SECC803S
KT88
Power Transformer
VR
SP
TRANS OUTPUT
BIAS BIAS
OUTPUT TUBE ADJUSTMENT
BIAS
BIAS-V4 BIAS-V3 BIAS-V2 BIAS-V1
BIAS
V2
V1
2B+3B+
+B 1 +B 2 +B 3
THERMAL FUSE
Operation SW
Fuse
+B 1

VACUUM TUBE STEREO POWER AMPLIFIER MQ-88uSE
7
Specifications
Continuous power output 25 W+25 W (6 Ω)
20 W+20 W (4 Ω, 8 Ω)
Total harmonic distortion 0.15 % (1 kHz, 6 Ω, 1 W)
0.5 % (20 Hz to 20 kHz, 6 Ω, 1 W)
Input sensitivity 790 mV/25 W
Input impedance 100 kΩ
S/N ratio 105 dB (IHF-A weighted, input short)
Frequency response 20 Hz to 20 kHz (+0, –0.5 dB)
10 Hz to 100 kHz (+0, –3.0 dB)
Input Line: 1 x Direct input, 1 x Variable input
Output Large type of speaker terminal × 1
Supplied functions [Front panel] Power switch, Volume
[Rear panel] Input terminal, Input selector, Speaker terminal, AC inlet
Circuiting system Mullard
Vacuum tube used 2 x ECC803S, 2 x ECC802S, 4 x KT88
Accessories • Power cable
• Owner’s Manual
• Safety cautions
• Terminal protection cap
Power source 230 V 〜(50 Hz)
Power consumption 220 W
150 W (no signal)
Max. external dimensions 440 (W) × 184 (H) × 230 (D) mm
Weight 15.8 kg (main unit)
* Specifications and appearance are subject to change without notice.

8
Before Asking for Repair Services
While the unit is used, an unusual phenomenon may be confused as a malfunction for a certain reason. Prior to asking our official sole
distributor of your country for repair services, please check the table below and read the operating instructions for the subsidiary devic-
es. If the cause of the malfunction cannot be identified, please contact your dealer. When we have once accepted your request for
repair services, inspection fees and traveling expenses may be claimed even though the unit is found to be normal.
Problem Cause Solution
No power is supplied even
though the power switch is
pressed ON.
• The power plug is disconnected from the
wall outlet, or it is not completely inserted.
• Insert the power plug in the wall outlet com-
pletely.
• The power plug is disconnected from the
AC inlet, or it is not inserted completely.
• Securely insert the power plug in the AC in-
let completely.
No sound is generated.
(for both left and right channels)
• The volume control is set at the minimum
level.
• Rotate the volume control clockwise to ad-
just the sound volume.
• The input switch is not set to the position of
the source to be played back.
• Set the input switch to the position of the
source to be played back.
• Cable connections are incomplete. • Make cable connections securely.
• The output level of the input device is set to
the minimum position.
• Adjust the output level.
No sound comes out from one
side.
• The connecting cable is not connected on
one side only.
• Make cable connections securely.
Humming sound (boon or zzz
noise) is generated.
• The ground side of the pin-plug cable has
no contact with the terminal.
• Make connections securely so that the
ground side of the pin-plug cable makes
contact with the terminal.
• The connecting cables are too close to the
power cable.
• Keep the connecting cables away from the
power cable.
• Induction noise is picked up from a power
transformer of another device.
• Install it distant from other devices.

VACUUM TUBE STEREO POWER AMPLIFIER MQ-88uSE
9
MEMO

LUXMAN CORPORATION, JAPAN
AG00987E54A
Printed in Japan
1-3-1 Shinyokohama, Kouhoku-ku, Yokohama-shi, Kanagawa 222-0033, Japan