Mitsubishi DA-A15DC User manual

a’. MITSUBISHI
STEREO POWER AMPLIFIER
A-AIODCIDA-AISDC
INSTRUCTION BOOK
Congratulations on your choice of the Mitsubishi
Stereo Power Amplifier Model DA-A10DC/DA-
A15DC. For best performance results, please read
this instruction book carefully before use.
WARNING—TO PREVENT FIRE OR SHOCK
HAZARD, DO NOT EXPOSE THIS APPLIANCE
TO RAIN OR MOISTURE.
For future reference a space has been provided below for
recording the serial number of your stereo power amplifj

ENGLISH
2
PRECAUTIONS
1. GENERAL
BE
SURE
TO
USE
YOUR
A.C.
POWER
SOURCE
Your
A.C.
power
is marked
on
the
rear
panel
of
this
unit.
Connection
to
any
other
power
source
may
cause
damage
to
this
unit
and/or
severe
electrical
shock.
DO NOT PLUG IN OR UNPLUG THE POWER
CORD WITH WET HANDS
There is a great danger of severe electrical shock if
the power cord is plugged in or unplugged with wet
hands.
Do
not
attempt
to
unplug
the
cord
from
an
A.C.
outlet
by
pulling
the
cord.
Firmly
grasp
the
plug to remove it from the A.C. outlet.
DO NOT ALLOW WATER OR ANY FOREIGN
MATTER TO GET INSIDE THIS UNIT
Should water or a metailic object accidentally fall
into this unit, immediately disconnect the power
cord and consult your authorized service dealer.
HANDLE THE POWER CORD WITH CARE
Do
not
bend
sharply
or
twist
the
power
cord.
If
the
insulation
becomes
damaged,
the
conductor
breaks,
or poor contacts occur, request service from your
authorized
service
dealer.
Continued
use
under
these
conditions, may cause fire or electrical shoek.
DO NOT TOUCH THE INSIDE OF THIS UNIT
There
are
high
voltages
inside
this
unit.
Never
re-
move
the
top
or
bottom
cover.
All
inspections
and
repair
including
fuse
replacement,
should
be
carried
out by your authorized service dealer.
DISCONNECT
THE
POWER
CORD
AT
THE
FIRST
SIGN
OF
TROUBLE
At the first sign of unusual noise, odor, or malfunc-
tion, disconnect the power cord and consult your
authorized
service
dealer.
Continued
use
under
these
conditions, may increase damage or cause additional
problems.
2. LOCATION
AVOID PLACEMENT IN DIRECT SUNLIGHT,
NEAR AIR CONDITIONER ETC.
This unit can become unstable if operated in ex-
tremely high or low temperatures. Place it in a well
ventilated area for proper heat dissipation. Avoid
placement in direct sunlight, near air corditioners,
poorly ventilated areas or in areas of excess humidi-
ty or dust. Do not block the ventilation holes.
3. CONNECTIONS
BE SURE TO TURN OFF THE POWER BEFORE
MAKING CONNECTIONS
This
is
to
prevent
damage
to
the
speakers
from
the
popping
noise
which
occurs
when
plugging
and
unplugging
cords.
USE
EXTREME
CARE
IN
MAKING
THE
COR-
RECT CONNECTIONS
If
you
reverse
the
R
(right)
and
L
(left)
leads,
you
will
reverse
the
stereo
location
of
R
and
L
channels.
MAKE CONNECTIONS SECURELY
If
any
of
the
plugs
should
become
loose
or
discon-
nected,
a
hum
may
develop.
If
this
is
not
corrected,
deterioration
of
sound
quality
and
possible
damage
to
the
speakers
may
result.
USE
ONLY
SHIELDED
CORD
FOR
THE
LEADS
Use
only
shielded
cords
for
interconnecting
com-
ponents.
Do
not
use
cords
longer
than
2m
(6'),
Ex-
cessive
lead
lengths
can
deteriorate
high
frequency
response
and
are
subject
to
interference
that
can
result
in
hum
or
noise.
DO
NOT
SHORT
THE
OUTPUT
OF
THE
POWER
AMPLIFIER
This
unit
incorporates
a
protection
circuit
so
that
power
transistors
will
be
protected
in
case
of
a
short.
Shorts
can
reduce
the
life
of
the
transistors
and
should
be
avoided.
USE
SPEAKERS
WITH
NOMINAL
IMPEDANCE
OF
4-16
OHMS
If
you
use
speakers
with
a
load
impedance
of
less
than
4
ohms,
the
protection
circuit
may
be
triggered
and
the
amplifier
output
muted.
WHEN
CONTROLLING
TWO
PAIRS
OF
SPEAK-
ERS
SELECTION
FROM
THE
COMPANION
PREAMPLIFIER,
ENSURE
THAT
THE
COM.-
BINED
IMPEDANCE
(BOTH
PAIRS
OF
SPEAK-
ERS
OPERATING)
IS
4
OHMS
OR
ABOVE
If
the
combined
impedance
is
below
4
ohms,
the
load
impedance
detector
circuit
may
operate
and
mute
the
power
amplifier
output.
The
combined
impedance
is
determined
with
the
following
formula.
Ax
COMBINED
IMPEDANCE
=
peel
(OHMS)
U871B005H04

FRONT PANEL TERMINOLOGY AND FUNCTIONS
8x8
= 4 (ohm
3 (ohms)
eg.
A: Nominal impedance of speaker A
B: Nominal impedance of speaker B
Please consult your audio dealer for additional
information.
4, OPERATIONS
BEFORE PLACING THE POWER SWITCH IN THE
ON OR OFF POSITION OR OPERATING
SWITCHES, ALWAYS TURN THE PREAMPLI-
FIER’S VOLUME (ATTENUATOR) CONTROL
ALL THE WAY DOWN
This is to protect the speakers from damage, that
can occur if the volume level is set high and the
power is turned on.
THERE WILL BE NO SOUND FOR A FEW SEC-
ONDS AFTER YOU TURN ON THE POWER.
THIS IS NOT A MALFUNCTON
This unit is equipped with a power supply muting
circuit which prevents popping noise when the pow-
er switch is turned on or off.
5. CARE
Wipe the cabinet with a soft cloth when it becomes
dusty. If it should get really dirty, dampen a soft
cloth in a weak solution of mild soap and water,
wring it out dry and wipe off. When finished, dry
completely with a soft dry cloth. Any volatile ma-
terials such as alcohol, thinner, benzine, insecticides,
etc, may remove the paint or damage the luster and
should not be used.
U871B005H04
1. THERMAL INDICATORS
lf the temperature of the heat sink reaches 60°C
(140°F), the thermal indicators change in color from
red to black. If the indicators turn black, turn the
power off and allow time for the amplifier to cool.
Resume operation when the amplifier cools to nor-
mal temperature.
1 2
2. HEAT SINKS
The heat given off by the transistors is radiated into
the air by the heat sinks.
3. TRANSFORMERS

ENGLISH
4, DUCTS
The power cord and connecting cords pass through
this ducts.
5. HANDLE MOUNTING SCREW HOLES
These holes are provided for mounting the handles.
For more details, see page 5.
6. ELECTROLYTIC CAPACITORS
7. POWER INDICATOR
This indicator illuminates when the POWER switch
is placed in the ON position.
8. POWER (Power Switch)
This switch is for turning this unit on and off. When
in the ON position, the power indicator is illumi-
nated.
REAR
PANEL
TERMINOLOGY
AND
CONNECTIONS
INPUT LEVEL (input Level Controls)
The
input
level
from
the
preamplifier
can
be
adjust-
ed
by
these
screws.
To
increase
the
input
level,
turn
these
screws
clockwise.
These
screws
are
normally
turned
fully
clockwise.
INPUT (Power Amplifier Inputs)
Connect
the
leads
from
the
preamplifier’s
outputs
to these inputs.
SPEAKERS
(Speaker
Terminals)
Two
pairs
of
speakers
may
be
connected
to
these
terminals.
Turn
the
screws
fully
counterclockwise,
insert
the
speaker
leads
and
tighten
the
screws
firmly.
SPEAKER
SELECTOR
(Speaker
Selection
Switch)
This
switch
controls
speaker
selection.
The
speaker
systems
can
be
selected
from
the
preamplifier
by
placing
this
switch
in
the
OFF
position
and
connect-
ing
the
supplied
SPEAKER
CONTROL
CABLE
to
the
preamplifier.
For
more
details,
see
Page
6.
REMOTE (Remote Terminal)
The
connection
for
one
end
of
the
SPEAKER
CONTROL
CABLE.
The
other
end
is
plugged
into
the
‘‘speaker
control’
terminal
of
a
companion
preamplifier
.
For
more
details,
see
page
6.
e
CONNECTING
THE
SPEAKERS
When
connecting
the
speaker
leads
to
the
SPEAK-
ERS
terminals,
there
is
danger
of
electrical
shock
or
fire
due
to
potentially
high
output
voltages.
To
avoid
this
danger,
connect
the
speaker
leads
as
follows.
@
Cut
back
the
outer
insulation
of
the
lead
to
a
distance
of
15mm
(5/8”’).
@
Twist
each
inner
conductor.
@
Turn
the
knob
of
the
SPEAKERS
terminal
fully
counterclockwise.
@
Insert
the
inner
conductor
into
the
hole
of
the
SPEAKERS
terminal.
Be
sure
that
the
end
of
the
insulation
is
inserted
into
the
hole
to
a
distance
of
3mm
(1/8’’).
@
Fasten
the
speaker
lead
to
the
SPEAKERS
terminal
by
tightening
the
knob
clockwise.
Inner
Conductor
Speaker
terminal
hole
Speaker leads
Speaker leads
CAUTION:
When
using
DA-A15DC,
use
more
than
18AWG,
SPT-2
cord
with
UL
label
for
speaker
leads.
‘
U871B005H04

U871BO05HO4
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(black)
Speakers
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SPEAKER SELECTOR
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UTPUT
5
SPEAKER
CONTROL
terminals
Preamplifier
when using companion
preamplifier,
connect to
SPEAKER CONTROL
terminals
—
HOW TO MOUNT THE HANDLES
@ Remove the screws and washers that are fas-
tened to the right and left side of this unit.
@ Mount the supplied handles to both side of
this unit as shown in the diagram.
A.C. POWER CORD
This cord is plugged
into the A.C. outlet.

ENGLISH
OPERATIONS
BEFORE OPERATING
Check the following items before placing the POW-
ER switch in the ON position.
e All other components are properly connected.
«The
position
of
the
SPEAKER
SELECTOR
switch
should
correspond
to
the
terminals
to
which
the
speakers
are
connected.
* The INPUT LEVEL control screws should be
turned fully clockwise.
Then place the POWER switch in the ON position
1. OPERATION
Select
the
tuner,
turntable
or
other
source
of
pro-
gram
material
and
advance
the
‘Volume
(Atten-
uator)"’
control
on
the
preamplifier.
You
should
now
be
receiving
the
program
from
the
speakers.
2.SPEAKER
SELECTION
FROM
THE
COMPANION
PREAMPLIFIER
if
you
are
using
the
companion
preamplifier,
speak-
er
selection
can
be
controlled
from
the
preamplifier.
@
Place
the
SPEAKER
SELECTOR
switch
to
the
OFF
position.
@
Connect
the
SPEAKER
CONTROL
CABLE
as
shown
in
the
diagram
(see
page
5).
@
Speaker
selection
may
now
be
controlled
from
the
preamplifier.
U871BO05HO4

BEFORE TAKING YOUR POWER AMPLIFIER IN FOR SERVICING .,...
First check to ensure that all other components are properly connected to this unit and are operating normally. Then check the following items.
SYMPTOM
CAUSE
REMEDY
©Power does not come on when the POWER
switch is turned on.
Power cord not completely plugged in.
© Fuse has blown,
© Plug in completely.
©Consult your authorized service dealer.
me
©No sound © Improper SPEAKER SELECTOR switch positioning. Correct the switch position.
oNominal speaker impedance is less than 4 ohms and o Use speakers with nominal impedance of 4 ohms
protection circuit is operating. or above.
© Speaker leads or plugs not completely plugged in. Plug in completely.
© Speaker (+) and (—) leads are touching. o Separate the leads.
©
Noise
©
Turntable
output
cord
too
close
to
power
cord.
©Plugs not completely plugged in.
©Put the turntable output cord as far as possible
from the power cord.
© Plug in completely.
nm oouauFSFSFSFSFFSSFFFFeEeEeeee
© Howling
© Caused by feedback. This occurs because speaker
* vibrations are being transmitted to the turntable.
© Place the speakers and the turntable as far apart
as possible. It is also helpful to put an insulator
under the turntable.
© Poor sound quality
© Too much power applied to speakers.
©No stereo effect and poor bass
© Speaker leads or plugs (+) and (—) are reversed.
© Adjust ‘‘Volume (Attenauator)‘’ on your
preamplifier.
©Correct the speaker leads or plugs connection.
©No sound for 5 — 7 seconds after power is
switched on.
-
©Muting circuit is operating to eliminate the popping
noise when power is turned on,
© This is not a malfunction.
U871B005H 04

ENGLISH
8.
DA-AlODC
/
DA-A15DC
SPECIFICATIONS
Power output
Total harmonic distortion
intermodulation distortion
(70Hz and 7kHz 4 : 1)
Power bandwidth
(IHF)
Frequency response
Input sensitivity/impedance
Damping factor
Channel separation
Hum and noise
Signal to noise ratio
(at rated power)
Slew rate
Power consumption
Dimensions
(Wx Hx D)
Weight
DA-A10DC
100W
continuous
power
per
channel,
both
channels
driven
into
8
ohms
from
15Hz
to
30kHz,
with
0.01%
THD
0.005%
at
S50W
per
channel,
both
channels
driven
into
8
ohms from 20Hz to 20kHz
0.008% at rated power, 8 ohms
0.01% at 1W per channel, 8 ohms
10Hz to 100kHz at 0.1% THD, 8 ohms
+0.1dB
from
20Hz
to
20kHz
at
rated
power,
8
ohms
+¢dB
from
DC
to
150kHz
at
0.5W
per
channel,
8
ohms
1V
(variable)
/50k
ohms
100 from 20Hz to 20kHz, 8 ohms
100dB at 1kHz
80dB at 20kHz
0.12mV (unweighted, closed circuit)
107dB (unweighted, closed circuit)
122dB (IHF, A network, closed circuit)
118dB (DIN, closed circuit)
109dB
(DIN,
47k
ohms//250pF
terminated)
30V /us at 50V peak to peak, 8 ohms
6OOW (IEC nominal)
390W at rated power, 8 ohms
240W (UL nominal)
425 x 170 x 285mm
(16-3/4 x 6-3/4 x 11-1/4”)
16kg (35-1/4 Ib)
DA-A15DC
150W
continuous
power
per
channel,
both
channels
driven
into
8
ohms
from
15Hz
to
30kHz,
with
0.01%
THD
0.005%
at
75W
per
channel,
both
channels
driven
into
8
ohms from 20Hz to 20kHz
0.008% at rated power, 8 ohms
0.01%
at
1W
per
channel,
8
ohms
10Hz
to
100kHz
at
0.1%
THD,
8
ohms
+
0.1dB
from
20Hz
to
20kHz
at
rated
power,
8
ohms
+°dB
from
DC
to
150kHz
at
0.5W
per
channel,
8
ohms
1V
(variable}/50k
ohms
100
from
20Hz
to
20kHz,
8
ohms
100dB at 1kHz
80dB at 20kHz
0.15mV
(unweighted,
closed
circuit)
107dB
(unweighted,
closed
circuit)
123dB
(IHF,
A
network,
closed
circuit)
119dB (DIN, closed circuit)
109dB
(DIN,
47k
ohms//250pF
terminated)
30V/us
at
50V
peak
to
peak,
8
ohms
9OOW (IEC nominal)
550W at rated power, 8 ohms
320W (UL nominal)
425 x 170 x 285mm
(16-3/4 x 6-3/4 x 11-1/4")
17.7kg (39 Ib)
Supplied.with: pin plug cord
speaker
control
cable
Design
and
specifications
are
subject
to
change
without
notice
for
improvements.
0877 BOOSHO4