Kenwood KR-4070 User manual

FM STEREO RECEIVER
KR-4070
gy
INSTRUCTION MANUAL
the sound approach to quality |
KENWOOD
To

INTRODUCTION
The
purpose
of
this
manual
is
to
acquaint
you
with
the
operating
features
of
your
new
receiver.
You
will
notice
that
in
every
detail
of
planning,
engineering,
styling,
operating
con-
venience,
and
adaptability,
we
have
sought
to
an-
ticipate
your
needs
and
desires.
We
suggest
that
you
read
this
manual
carefully.
Knowing
how
to
set
up
your
receiver,
to
the
best
advantage,
will
enhance
your
listening
pleasure
right
from
the
start.
You
will
also
become
aware
of
the
ease
with
which
you
can
adjust
your
receiver
to
meet
your
special
re-
quirements.
SERIAL NUMBER
Record your SERIAL NUMBER on the
spaces designated on the warranty card. You will
find the serial number on the back of the unit.
AFTER UNPACKING
After unpacking, we recommend you inspect
and examine the unit for any possible shipping
damage. If your unit is damaged or fails to
operate, notify your dealer immediately. If your
unit was shipped to you directly, notify the
shipping company without delay. Only the
consignee (the person or company receiving the
unit) can file a claim against the carrier for
shipping damage.
We recommend you retain the original
carton and packing materials to prevent any
damage should you transport or ship your unit in
the future.
PRECAUTIONS ON INSTALLATION
a) Avoid locations subject to direct sunlight.
b) Avoid high or low temperature extremes.
c) Keep the unit away from heat radiating
source and magnetism generating source.
d) Choose locations with as little vibration and
dust as possible.
WARNING:
TO PREVENT FIRE OR SHOCK
HAZARD, DO NOT EXPOSE THIS
APPLIANCE TO RAIN OR MOIS-
TURE.
2 KR-40701K}
IMPORTANT!
1.
Units
shipped
to
U.S.A.
and
Canada
are
designed
to
operate
on
120
volts
AC
only
and
are
not
equipped
with
an
AC
Voltage
*
Selector
Switch.
Therefore,
the
following
©
:
description
on
sucha
switch
should
be
:
disregarded.
..
: :
‘
2.
Units
shipped
to
all
other
countries
are
Q
equipped
with
an
AC
Voltage
Selector
~
Switch
on
the
rear
panel.
The
following
;
description
on
this
switch,
“AC
Voltage
<
Selection”,
should
be
carefully
read.
;
AC VOLTAGE SELECTION
This unit operates on 120 volts, 220 volts or
240 volts AC. The AC Voltage Selector Switch is
set to the voltage generally available in the
country where the unit is shipped. It is important
to
make
sure,
before
connecting
the
power
cord
to
your
AC
outlet,
whether
the
setting
position
of
this
switch
corresponds
to
your
voltage.
If
not,
it
must
be changed to the proper setting in accordance
with the direction below.
NOTE:
Our warranty does not cover damage caused by excessive
line voltage due to improper setting of the AC Voltage
Selector Switch.
Stopper plate
Screw
@
|
Lever
i)
i)
AC
120V~
C}
C)
Position
AC
220V~
Position
AC
240V~
Position
)
@
©
1. Remove screw and stopper plate
2. Slide lever to your line voltage.
3. Lock lever with stopper plate and screw.
AC VOLTAGE SELECTOR SWITCH

5
CONTENTS
CONNECTING
INSTRUCTIONS
000...
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6
OPERATING
INSTRUCTIONS...
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cet
eter
ttetereaeeens
10
POINTS TO BE CHECKED PRIOR TO SERVICING ........ eee 12
SPECIFICATIONS ooo... cee cece ect eeeeetenceete te tttettteetenas 12
FEATURES
Low
noise
cascade
junction
type
FET
and
frequency
linear
type
precision
3-ganged
var-
iable
capacitor
are
empioyed
in
the
FM
front
end.
These
are
followed
by
high
selective
IF
section
and
phase
locked
loop
system
IC
in
the
MPX
circuits.
These
highly
retiable
elements
will
give
you
stable
FM
reception.
.
AM
section
is
equipped
with
high
selectivity
ceramic
filter
and
high
performance
dual-in-
line
type
IC.
This
will
promise
you
optimum
reception.
Employs
large
size
of
signal
and
tuning
meters.
,
Employs
large
size
of
dial
stroke
of
10-5/8”
{270
mm).
Equipped
with
convenient
muting
circuit
which
automatically
silences
interstation
noise.
40
watts
per
channel,
minimum
RMS
at
8
ohms,
from
20
Hz
to
20
kHz
with
no
more
than
0.1%
total
harmonic
distortion.
7.
10.
11.
12.
13.
Power amplifier section employs differential
amplifier with high stability and low
distortion in first and second stages, and, di-
rect coupled circuit, in all stages.
Adoption of the Kenwood ASO (area of safe
operation) detection limiter system for the
protection circuit which protects power tran-
sistor.
Pre-amplifier
is
equipped
with
operational
IC
amplifier
of
single-in-line
type,
and
this
will
assure
you
low
noise,
low
distortion
and
increase
of
dynamic
range.
Devised
to
improve
stability
in
power
source
and
sound
quality
by
employing
two
electro-
lytic
capacitors
of
7500uF.
Decreased wires thanks to a large-sized
printed circuit board.
Two
pairs
of
speakers
can
be
used.
Equipped with a massive heat sink.
kR-4070(K) 3.

OUTDOOR FM ANTENNA
When a 75 ohm antenna is used for
connecting to the antenna terminals,
the 300 ohm terminals should not be
used, and conversely.
INTERCONNECTING
DIAGRAM
752
coaxial
cable
T-TYPE FM ANTENNA
AM FERRITE BAR ANTENNA
See page 9.
y
Prono “us
INPUT ——TAPE——
PLAY REC/PLAY REC
aR) obi
TO AM OUTDOOR
ANTENNA
TURNTABLE
4 — KR-4070(k)
OIN cord
as =.
7 fieees attOe' 58
TAPE DECK
TO AC OUTLET
Leh
Rch
Lch
Rech
SPEAKER
SYSTEMS
A
SPEAKER
SYSTEMS
B

CONTROLS
AND
THEIR
FUNCTIONS
@KENWOCIO am-em evened! necever
(aria =
Power
SPEAKER
® POWER/PHONES/SPEAKERS switch
A combined switch for power, headphones and speaker
selection.
POWER OFF........ Receiver off.
PHONES .............. Speakers cut off (headphones can be
used).
POETS To listen to speakers connected to the
SPEAKERS A terminals.
Ee To listen to speakers connected to the
SPEAKERS B terminals.
AB ie To listen simultaneously to speakers
connected to the A and B SPEAKERS
terminals.
@ PHONES jack
Insert a stereo headphone plug into this jack for private
listening. The speakers are silenced when the SPEAKERS
switch is set to PHONES position.
@ BASS and TREBLE controls
BASS
control
.......
Turning
it
clockwise
increases
low
fre-
quencies
and
counterclockwise
decreases
it.
TREBLE control.... Turning it clockwise increases high
frequencies and counterclockwise
decreases it.
@ BALANCE control
This contro} adjusts unequal volume from any program
source in right and left channels. The left channel is
accentuated
when
this
control
is
turned
from
center
toward
the left side, and conversely.
@ VOLUME control
This control adjusts simultaneously volumes in both chan-
nels {right and teft). Set it to your own most satisfactory
listening tevel.
© LOUDNESS switch
This switch boosts bass and treble tones at low listening
levels. Our ears have less sensitivity to low and high
frequencies at tow listening levels and this switch
compensates for this deficiency. This switch should be off
when listening at normal and high levels.
@) TAPE switch
Depress this switch when using a tape deck for tape
playback, or when monitoring a tape during recording.
NOTE:
Except for tape playback, make sure it is in the
“SOURCE” position.
SELECTOR switch
Switch positions and functions are as follows:
AM... ee To receive AM broadcast.
AUTO/MUTING ... To receive both FM mono and stereo
broadcasts. Automatic switching
operates between FM mono and stereo
broadcast. This position also silences
the interstation noise on the FM band.
. To receive FM mono broadcast.
. To operate a turntable connected to
the PHONO jacks.
To select source connected to the AUX
jacks.
@ TUNING knob
Select the desired AM or FM station while observing the
SIGNAL and/or TUNING meters for optimum tuning.
FM STEREO indicator
With the SELECTOR switch set to AUTO/MUTING position.
the STEREO indicator lights during an FM stereo broadcast
reception. However, it does not light during an FM mono
broadcast reception.
@@ TUNING meter
This meter is used for precise tuning to the center of an FM
channel. Turn the tuning knob until the meter pointer is in
the center of the meter scale. This provides maximum
separation and minimum distortion.
() SIGNAL meter
This meter indicates signal strength for AM and FM.
Maximum deflection indicates best receiving condition.
KR-4070(K) 5

CONNECTING
SPEAKER CONNECTION
In connecting only one pair of speakers, con-
nect the right speaker to [R] and the left speaker
to [L| of the SPEAKERS A terminals. Should (+)
or (—) of either right or left channel be reversely
connected, sounds at the center section will be
adversely affected by the lack of separation. To
connect an additional pair of speakers, connect
the right speaker to [R] and the left speaker to
of the SPEAKERS B terminals.
Sound cannot be heard when the SPEAK-
ERS switch on the front panel is set to the A+B
position and only one pair of speakers (connected
to either SPEAKERS A terminals or B ones) are
used. This is because A and B speaker circuits are
in series and is not an indication of any trouble.
When connecting the speaker leads to the
speaker terminals, make sure that the bare wires
at the tips of the speaker leads do not touch the
adjacent terminal.
{t is recommended that the wires of
individual speaker lead tips are soldered or they
are stranded together to eliminate any possibility
of short-circuits forming in the speaker connecting
network.
INSTRUCTIONS
——
10 rom
———— a @_ Remove insulation
from lead tip.
@ Strand wire.
SPEAKER LEAD TIP
Insert the
Loosen the
screw wire
Tighten the
screw
NOTE:
The impedance of each speaker should be 4 ohms or more
when only one pair of speakers are used or when two pairs
of speakers are simultaneously used (A+B).
RIGHT
PHASING OF THE SPEAKERS
Speaker phasing can be determined in the following manner:
1. Set the SELECTOR switch to FM (MONO).
2. Adjust the VOLUME control to the desired listening level.
3. if the sound comes directly from the front. the speakers are in phase. If the sound
comes from both sides and there is a noticeable loss in low frequencies, the speakers
are out of phase. In this case reverse the leads on one speaker.
Ey] (Leet)
6 — KR-4070{K)

CONNECTING
TURNTABLE CONNECTION
The two shielded audio cables from your
stereo turntable are normally terminated with
phono plugs. Connect the left channel of the
turntable to[L] of the INPUT PHONO jack and the
right channel to [R! of the INPUT PHONO jack.
If the turntable has a grounding wire, con-
nect it to this unit's GND terminal to avoid hum.
TAPE DECK CONNECTION
Recording
A tape deck can be connected for recording
as follows: the left channel input of the tape deck
to of the TAPE REC jack, the right channel
input of the tape deck to [R] of the TAPE REC jack.
Playback
A tape deck can be connected for playback
as follows: the left channel output of the tape deck
to of the TAPE PLAY jack, the right channel
output of the tape deck to [R? of the TAPE PLAY
jack. ‘
DIN CONNECTOR (REC/PLAY CONNECTOR)
if your tape deck is equipped with a DIN
connector, connect it to the TAPE REC/PLAY
connector with a DIN connecting cord. A DIN
connector enables recording and playback with
this single cord.
NOTES:
1) Please note that the REC/PLAY connector corresponds
to the TAPE REC and PLAY — the signal must be con-
trolled with TAPE switch on the front panel. ,
2) When a DIN cord is used for connecting to the tape
deck, the PLAY and REC jacks should not be used.
AUX (AUXILIARY INPUTS)
High level AUX input jacks are for mis-
cellaneous sources, such as extra tape decks, TV
sound outputs, and other external components.
INSTRUCTIONS
TURNTABLE
GND (CINPUT
PHONO = AUX
Ground wire
TAPE DECK
AC OUTLETS
The AC outlets on the rear panel of the
receiver may be used to supply power to other
components, such as a turntable, tape deck, etc.
1. SWITCHED outlet
This outlet is controlled by the POWER
switch on the front panel. (The capacity is
200 watts maximum.)
2. UNSWITCHED outlet
This outlet delivers power at all times. (The
capacity is 200 watts maximum.)
NOTES:
1} Units shipped to the European countries are not
equipped with the AC OUTLETS.
2) Do not connect any equipment whose power consump-
tion exceeds the capacity of each outlet.
KR-4070{K) 7

CONNECTING
FM ANTENNA CONNECTIONS
Since
FM
broadcast
signals
travel
along
a
straight
and
direct-line
path,
they
become
rather
weak
behind
hills
and
buildings
even
in
the
vicinity
of
a
transmitting
station.
FM
signals
also
become
weak
in
areas
distant
from
a
station
even
though
there
may
not
be
any
obstruction
to
the
direct-line
path
of
the
signal.
Therefore,
a
good
FM
antenna
should
be
installed
in
the
most
effective
manner
for
the
best
possible
FM
reception.
FM Outdoor Antenna
In areas at a greater distance from the
transmitting
station,
the
use
of an
outdoor
antenna is highly recommended. It is available in
various
types.
For
reception
of
stations
located
in
many
directions,
a
non-directional
type
antenna
will
offer
better
results.
When
using
a
directional
antenna,
always
orient
it
for
the
best
reception
of
the
desired
station.
The
correct
position
will
be
indicated by maximum deflection of the SIGNAL
meter on the unit.
Connections
should
be
made
as
indicated
by
figures.
Keep
FM
antennas
away
from
roads
to
avoid
noises
made
by
the
ignition
of
car,
motorcycle,
etc.
NOTE;
Consult
audio
dealer
for
detailed
information
of
FM
outdoor
antenna installation.
T-type Antenna
In
areas
close
to
the
transmitting
station,
a
simple
T-type
antenna
may
suffice.
It
should
be
remembered,
however,
that
the
pickup
of
reflections
(similar
to
“ghosts”
on
TV)
will
result
in
poor
stereo
reception.
These reflections must therefore be reduced
to
a
minimum,
either
by
careful
orientation
of
the
indoor
T-type
antenna
or,
if
this
will
not
eliminate
them,
by
using
a
more
directional
outdoor
type
antenna.
Spread
the
2
arms
of
the
antenna
horizontal-
ly
and
while
listening
to
an
FM
station,
position
them
for
the
best
reception.
The
antenna
can
then
be
taped
to
a
wall
or
ceiling.
8 — kR-4070(K)
INSTRUCTIONS
752, coaxial
cable
NTENNAY
ANTENNA
FM
seen |
zg
t
----+-6 ©
GND AM
XN

- CONNECTING
AM ANTENNA CONNECTION
Normally, position the ferrite bar antenna
for best reception while listening to an AM station
as described on page 10.
AM Indoor Antenna
The ferrite bar antenna employed on the rear
panel assures optimum AM reception.
AM Outdoor Antenna
In fringe areas or in locations surrounded by
steel frame buildings where satisfactory reception
cannot be obtained with the ferrite bar antenna,
an AM outdoor antenna should be connected to
the AM terminal.
GROUND
It is advisable to connect the GND terminal
on the rear panei to the ground by using a buried
grounding rod or iron-made water pipe to reduce
the noise and ensure safety. However, never use
a gas pipe for this purpose.
DIN-TYPE ANTENNA JACKS
Units shipped to European countries are
equipped with the DIN-type antenna jacks on the
rear panel.
NOTE:
Consult audio dealer for detailed information on making con-
nections.
INSTRUCTIONS
Keep the AM ferrite bar antenna away
from the rear panel.
AM ANTENNA SETTING
ANTENNA GND
Ground wire
ROUND
TO OUTDOOR AM ANTENNA
To KR-4070
DIN-type feeder
antenna jacks
separator
coaxial cable
To DIN antenna
outlet
DIN-TYPE ANTENNA CONNECTOR
PRECAUTIONS FOR SAFETY
@ Switch off the unit and disconnect the power plug
from your AC outlet immediately if the abnormality
(smell, smoke, etc.) should take place.
@ When you connect or disconnect the power plug from
your AC outlet, never do it with wet hands to avoid
unexpected accident from electric shock. Besides. do
it by holding the power plug itself.
@ Disconnect the power plug from your AC outlet when
it begins to thunder terrifically. Aliso. it is safe to
disconnect the antenna feeder {or coaxial cable) from
the unit if an outdoor antenna is installed. Do not
touch the antenna feeder {or coaxial cable) discon-
nected then.
@ It is desirable to disconnect the power plug from your
AC outlet when you leave your house for a long time.
@ The power cord must not be pulled strongly. nor bent
@ Do not put a heavy thing on the power cord.
@ Do not put on and near the unit what contains water
@ Do not put in the unit the inflammable (paper, cellu-
@ Never dismantte the case from the unit and touch the
* * *
forcibly, nor scratched, nor extended by connecting an
extra cord. This will damage the cord and be a cause
of electric shock and a fire.
* * *
(vase. etc.).
loid, etc.) and the metal (needle. hairpin, coin, etc.).
* * *
internal part. Never modify the internal part.
Otherwise, the danger of electric shock will be in-
curred.
KR-4070iK) 9

OPERATING
INSTRUCTIONS
Prior to turning on the unit, set each control and switch as below.
e TAPE “SOURCE”
e LOUDNESS “OFF”
e VOLUME “MIN”
e BALANCE Center Position
e TREBLE Center Position
e BASS Center Position
accordance with the item to be operated.
Next, turn on the unit and set the SPEAKERS switch to “PHONES”, “A”,
“B” or “A+B” in
FM RECEPTION
1. Set the SELECTOR switch to FM AUTO
MUTING.
2. Turn the TUNING knob to select your sta-
tion. Best reception is obtained when the
TUNING meter pointer is exactly in the
center and the SIGNAL meter pointer
deflects to the extreme right.
TUNING
FM Reception
3. Adjust volume and tone quality. °
NOTE:
It may be impossible to eliminate noise from an FM stereo
broadcast if the signal is extremely weak. In such a case
the relative signal strength can be improved by setting the
SELECTOR switch to FM MONO. While the stereo effect
will be lost, a great deal of the noise can be substantially
eliminated.
10 = KR-40701K)
AM RECEPTION
= Set the SELECTOR switch to AM.
2. Turn the TUNING knob to select your sta-
tion. Best reception is obtained when the
SIGNAL meter pointer deflects to the ex-
treme right.
AM Reception
3. Adjust volume and tone quality.
TURNTABLE OPERATION
1. Set the SELECTOR switch to PHONO.
2. Operate the turntable.
3. Adjust volume and tone quality.
AUX JACKS UTILIZATION
To play component connected to. the AUX
jacks, proceed as follows:
1. Set the SELECTOR switch to AUX.
2. Operate the component connected.
3. Adjust volume and tone quality.