Luxman M-700U User Manual

STEREO POWER AMPLIFIER

M-700u

Owner`s Manual

Contents

Precautions ············································································································· 1

Features of This Unit ································································································ 2

Names and Functions ······························································································ 4

Connections ············································································································ 8

Block Diagram ······································································································· 12

Specifications ········································································································ 13

Before Asking for Repair Services ·········································································· 14

STEREO POWER AMPLIFIER M-700u

Precautions

Installation place

Install this unit in a location where good ventilation and heat

radiation is assured.

Especially, placing 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 malfunc-

tion even if heat is efficiently released.

Ventilation holes

Do not block the ventilation holes of the top and bottom pan-

els. 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

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*

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Wall

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 is generated

shortly after the power supply is turned on.

If the volume control is moved 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 of the

input device such as a control amplifier shall be set to a low

level at first and adjusted according to your taste after 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 lights

up to show that this product is in the standby state. Please

consult your dealer when the protection circuit is sometimes

activated even after turning off the switch, disconnecting the

power plug from the wall outlet, and connecting it again after

a while.

Repair and adjustment

When repair and adjustments are needed, please ask the

dealer where you bought the unit.

Precautions in connecting with other
components

When connecting this product with a control amplifier and

such, be sure to turn off the power of this product and all oth-

er connected devices. Failure to observe this may generate

a strong noise resulting in speaker damage or 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.

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.

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 often damage the exterior.

SAFETY CAUTIONS

CAUTION

Exercise extra care when this unit is unpacked, assembled,
transported, and installed because this unit is heavy.

1

Features of This Unit

4 parallel push-pull output stages

4-parallel push-pull amplification circuit structured with

3-stage Darlington.

Rated output of 120 W+120 W (8Ω), 210 W+210 W (4Ω).

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 for the main amplifier to maintain the pure sound quality

that is almost non-feedback.

With ODNF’s latest version 4.0, in the amplification circuit,

the first stage is 4-parallelized and the second stage is con-

nected with Darlington. Due to these improvements, the low

impedance and high S/N ratio of the transmission circuit have

become possible.

In addition, the input stage of the error detection circuit is

3-parallelized to improve distortion and noise.

BTL connection mode

The BTL connection mode with use of 2 units of this product

has achieved a high-quality and high-power monaural ampli-

fier structure.

2-channel input selector

Switching between unbalanced input of RCA terminal sup-

porting large plugs and balanced input of XLR terminal manu-

factured by Neutrik that supports high-grade balanced signal

transmission is possible.

Balanced input phase selection

Balanced input phase selection switch is equipped, which is

useful for the case of connecting foreign-made input devices.

Selector relay

Selector relay with high sound quality used in Luxman ampli-

fiers enhances the separation and crosstalk performances.

High-inertia power supply

L and R separated high-inertia power supply circuit combin-

ing a large-capacity EI-core-type power transformer with cus-

tomizable 10,000μF × 8 block capacitors are used.

2

STEREO POWER AMPLIFIER M-700u

4-parallel speaker relay

Impedance of speaker output lines is reduced thanks to

4-parallel structure of speaker relays with low resistance val-

ue for each channel.

Loopless chassis

The independent construction of a loopless chassis structure

eliminates the rise of increased ground impedance caused by

chassis current.

Schottky barrier diode

In the power supply rectifier circuit, schottky barrier diode

manufactured by Nihon Inter Electronics Corporation that has

less switching noises and higher conversion efficiency to the

DC voltage is applied.

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 processing on the

core wire.

High-grade analog meter

Large-sized analog meter with shower light is equipped. Light

OFF/meter OFF is selectable.

Large type of speaker terminals

Speaker terminals of right and left identical layout, compatible

with Y lugs, and allow extra-thick speaker cables to be con-

nected easily.

AC inlet

This inlet enables the connection with an external power ca-

ble.

Cast-iron insulator

The gradation cast-iron insulator that clears unnecessary ex-

ternal vibration and strongly supports the weight of this unit

is equipped.

3

Names and Functions

LINE BAL LINE

LINE

BAL LINE

6 753 421 8

Front panel

1 . Standby indicator (STAND BY)

Indicates that this unit is in the standby state.

This indicator lights up when the operation switch is turned

off after the main power switch on the rear panel is turned

on.

When the operation switch is turned on and when the main

power switch is turned off, this indicator turns off.

2. Operation indicator (OPERATION)

Blinks (for approx. 15 sec.) when the unit is in a muting

mode, when the operation switch is turned on. Then it lights

up when the unit is in the operation state afterward.

3. Operation switch (OPERATION)

Turns this unit from the standby state to operation state.

When the main power switch on the rear panel is turned

on to set this unit to the standby state, turn this switch on.

Then this unit is set to the operation state.

When wiring or connection is performed, be sure to turn off

this switch.

4. Input indicator (LINE/BAL LINE)

Indicates the input selected with the input switch.

5. Input switch (INPUT)

Selects the unbalanced input terminal (LINE) or balanced

input terminal (BAL LINE), both of which are located on the

rear panel.

Every time this switch is pressed, the selection changes as

follows: LINE

Factory default: LINE

When this switch is toggled, the input/output muting circuit

is activated and no sound is generated during the time.

→BAL LINE→LINE→BAL LINE→LINE…

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