Yamaha CR-840 User manual

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YAMAHA offers you thanks and congratulations on your choice of the CR-840 Receiver.
Embodying the most up-to-date and useful features, it combines superb broadcast reception
with the finest audio quality, and is currently setting new standards for receiver perform¬
ance in its class.
1. All-in-One Excellence
Accurately matched performance specifications,
functions, and controls, provide an overall per¬
formance which fully measures up to Yamaha's
high tuner, preamplifier, and power amp standards.
2 . Noise-Distortion Clearance Range
This is the basic concept for the audio section.
The CR-840 offers an extremely wide range of
output power level for which both noise and dis¬
tortion are below the rated value, to ensure a wide
dynamic range in actual use.
3. Direct Assessment of Differential Gain
This sophisticated technique enables Yamaha to
combine high station-receiving ability, razorsharp
tuning, and ultra-low distortion in the tuner
section.
4. Optimum Tuning System
The OTS system will take over from you the
fine-tuning needed to obtain minimum distortion
and maximum stereo separation, so that all FM
stereo programs are heard at their best.
5. T win-Meter FM Tuning with Signal Quality
Reading
Both signal strength and center-zero FM tuning
meters are provided on the CR-840, with the signal
strength meter doubling as a signal quality meter
on FM.
8. Comprehensive Tone/Filter Controls
Both bass and treble controls have completely
"FLAT" central positions. High and Low filters
are also provided.
7. Continuous Loudness Compensation
This Yamaha 'special' fully compensates for the
ears' reduced sensitivity to bass and treble
frequencies at low listening levels, whatever your
normal maximum listening level.
8. Auto DX Circuit for High Quality Reception
The Auto DX Circuit permits the IF range to be
automatically modified according to the quality of
the broadcast being received, thereby ensuring
high sensitivity and high selectivity in reception.
Special Featurers of the CR-840 Receiver. ... 2
Cautions—Read this before Operating
Your CR-840 .. 3
Front Panel and Controls . .
.4
Connection Diagram ....
. 7
Rear Panel and Connections
I. 8
Broadcast Reception ....
.10
Listening to Records .1. . . .
LOUDNESS, FILTERS, and
TONE Controls.
.14
The Special REC OUT Selector Switch
.... 15
Tape Playback and Recordina J .
.16
1 Specifications.
. 18
Troubleshooting J.
...20
Block Diagram.. ■
.22
Schematic Diagram.
.23
IMPORTANT!
Please record the serial number of your unit in the
space below _
Model Name CR-840
Serial No. ___
The serial number is located on the rear of the
chassis. Retain this Owner's Manual in a safe place
for future reference.

The CR-840 is a high performance AM/FM stereo
receiver, with excellent selectivity, sensitivity,
low distortion, and high output power. This
manual is required reading if you are to get the
best from its special features and controls.
Do not drop or otherwise jar the CR-840, which
is a precision electronic instrument.
Do not place the CR-840 where it will be
exposed to direct sunlight, excessive heat (for
instance over a radiator), cold, moisture, or dust.
Do not use chemical solvents (such as benzene or
alcohol) to remove traces of dirt. Wipe only with
a soft, slightly damp cloth.
The CR-840 is so heavy. When installing, make
sure to select a firm and solid base.
Do not attempt to carry out internal adjustments
or repairs. Leave these to your local authorized
service representative.
Do not assume your CR-840 is faulty before
checking the 'Trouble Shooting" list provided
on page 20 to 21.
Do not connect other audio equipment to the
spare AC outlet sockets on the rear panel if the
equipment will require more power than the
outlets are rated to provide.
Keep this manual in a safe place for future refer¬
ence, and refer to it frequently until you are
completely familiar with all CR-840 controls and
functions.
Warning - to prevent fire or shock hazard, do
not expose this appliance to rain or moisture.
Operate all switches and knobs in accordance
with the instructions. Avoid applying undue
force, which should never be necessary, and do
not attempt to use in between switch positions.
3

^POWER OFy/OFF Switch
Switch ON to activate the main electrical supply.
Leave OFF while familiarizing yourself with the
controls, and while connecting other audio equip¬
ment.
@POWER( Power Indlicstsor)
This Jight-emitting diode gives visible indication of
the Power being ON.
§SIGWAL QUALITY IVSsSer
This meter indicates the signal strength for both
AM and' FM stations, and also indicates the
presence of FM interference by oscillations of the
meter indicator, with the amplitude of the indica¬
tor fluctuations showing the extent of the
interference.
0The FM/AM Tuning E!e®ie
The upper scale gives FM station frequencies in
MHz and the lower scale gives AM frequencies in
kHz. On the right-hand side of the front panel, the
LEDs light to indicate FM or AM operation.
4

This is used when tuning in FM stations: the indi¬
cator points to dead center when the station is
perfectly in tune.
©DIAL POINTER
Turn the tuning knob to align this pointer to a
desired station.
@HEC OUT SELECTOR
This selects which program source will be recorded,
just as input selector selects which program source
will be heard. With the CR-840, you can listen to
one program source while recording any other
{copy a friend's tape while listening to FM, etc.).
This eliminates "dead" time while you are taping,
permitting you to enjoy the use of your CR-840
while recording.
©IWPUT SELECTOR
This selector switch is used to select the program
source of your choice, whether it be Phono, Tuner,
one of two tape decks, or Aux (for use with 8-track
tape cartridge playback, etc.). The phono switch
position input circuit is designed to operate with
normal moving magnet (MM) type cartridges. Use
of some moving coil (MC) type cartridges is possi¬
ble, but, other low output moving coil cartridges
may require use of a step-up transformer or a head
amplifier.
Use this control to give the volume of sound that
you require. Always start with it turned fully to
the left (counter-clockwise) at the "0" position
before turning it up to the volume level you re¬
quire (clockwise).
If the DX indicator light is on when the IF MODE
switch is in the Auto ( M ) position, it signifies
that the tuner is operating in the DX MODE. When
tuned to a powerful local station, the local mode
takes over.
(AM iodlea^or)
This indicator comes on when receiving an AM
broadcast.
USTEREO (Stereo Indicator)
This indicator comes on automatically when FM
stereo broadcasting is received and goes out auto¬
matically when there is monaural reception.
§BLEND ( Blend Indicator 8 )
This indicator comes on automatically when the
signal you receive is weak. In weak reception areas,
when a hissing or high pitched noise makes for
poor FM stereo reception, the blend circuit will
cut in to cancel the high-range noises. It operates
when the IF MODE switch is in AUTO ( MJ.
®OTS(OTS Indicator 1 )
If the OTS indicator light is on when the FM
Muting/OTS switch is in the ON ( J8L) position, it
signifies that the Optimum Tuning System will
correct any slight mis-tuning, to assure optimum
reception of FM stations.
§PHONES A and B Jacke
Two headphone jacks are provided. Plugging into
the jacks does not cut-off power to the speakers,
so it is necessary to use the off position of the
speaker selector switch if you do not want the
speakers to function.
fSPEAKER
With this switch you can select either (A or B) or
both (A + B) of two sets of stereo speaker systems.
§LOCAL (Local Indicator)
It lights up during Local (general) reception. When
the IF Mode Switch is in Local ( -**•), however, it
remains lighted regardless of distant or local re¬
ception.
®LQW and NIOH FILTERS
The low filter gives a sharp 12 dB/octave cut-off
below 25Hz. The high filter has 6 dB/octave cut¬
off slope at frequencies above 8 kHz.

©LOUDWeSSB Control
This boosts the extreme low and high frequencies
to compensate for our ears 7 reduced sensitivity to
these frequencies at low volumes. Set it to the
FLAT position while the VOLUME control is set
to your normal maximum listening level. Turning
it counter-clockwise will reduce the volume while
retaining the natural balance between low and high
frequencies.
||BASS and TREBLE Controls
The bass and treble controls have a low turnover
frequency of 350 Hz and a high turnover frequen¬
cy of 3.5 kHz respectively. In the flat positions,
the tone control circuits 7 frequency response is
completely flat.
@ PHESEWCE Control
This control, centered about 3 kHz, readily
adjusts for mid-range characteristics.
iOALANCIE Control
The balance knob controls the difference in out¬
put volume between the L and R {left and right)
stereo channels. Set this control to the center "Q"
position, at which there is a click stop, unless you
need to correct for a lack of balance between the
audio level of the two channels, or to correct for
a listening position which is not equidistant from
the two speakers. The balance control reduces the
volume from the left-hand speaker when turned
clockwise, and reduces that from the right-hand
speaker when turned counter-clockwise.
©IVSQDe Switch
This gives the choice of stereo or monaural
reproduction. Note that in the mono position the
amplifier section will reproduce all sounds {includ¬
ing FM stereo programs, etc.) monaurally.
® ADAPTOR Bwi&ch
When connecting a Graphic Equalizer, Dolby Unit
or any other audio equipment to Adaptor termi¬
nals, set the ADAPTOR switch to ON. Make sure
to keep it OFF when not used.
Leave OFF while not connecting any other audio
equipment.
®IF MODE Bwifcoh
With this switch in Auto { M ), Local {general)
function automatically switches to DX {long
distance) so please leave the switch in this position
for normal use. Switching to Local ( -) position
compells the tuner to stay in the Local mode
regardless of remote or local signal reception.
© SVB UT1IMG /OTS Switch
When this switch is in the ON position, the Opti¬
mum Tuning System {OTS) will minimize the
effect of any mis-tuning, and will ensure continued
optimum reception of FM stations. In the OFF
position, accurate manual tuning is essential. Even
in the ON position, however, OTS is automatically
switched off when you touch the tuning knob,
permitting manual tuning. The FM muting
function ensures that both inter-station noise and
weak signal strength stations will be muted. In the
OFF position even the weakest stations will be
heard.
® TUNER FM/AM Switch
This determines whether AM or FM stations will
be received.
0TtJWII%Se Knob
The large tuning knob gives smooth and positive
station selection, with a precision flywheel mecha¬
nism.
6

ANOTHER PIECE TAPE DECK-1 TAPE DECK-2 GRAPHIC EQUALIZER
AUDIO EQUIPMENT
TURN TAEILE
(with MM Type Cartrigde)
7

M AfyT 75^ UNBAL
The 75£2 UNBAL (unbalanced) terminal is used
for an unbalanced type 75£2 coaxial cable.
(Refer toPIO).
§Antenna Connections
Detailed instructions on AM and FM reception are
given on pages 10 to 12, but a quick check of
CR-840 tuner functions can be carried out by
connecting the T-type indoor antenna provided
with the CR-840 to the terminals marked 300^2
BAL.
Attach the two arms of the "T", fully extended,
to the ceiling or walls of your room. The quick
check can be carried out with the selector switches
vertical and all push button switches in the out
( JIL) positions, except for the speakers selector
switch (when you wish to hear the output on your
speakers rather than using headphones).
^SPEAKER
The CR-840 can handle two sets of speakers (A
and B), with selection of either, both, or neither,
by use of the Speakers Selector switch on the
front panel. Speakers should have impedances
between 4 and 16 ohms, but when the two speaker
sets are to be used at the same time, connect only
speakers with impedances between 8 ohms and 16
ohms. Use speakers rated to take the full 60 watts
of output power, or set the volume control so that
the rated maximum speaker input power is not
exceeded. Volume level should be reduced
immediately whenever there is increased distortion
or a sense of strain which indicates that the
speakers are being overloaded.

SPEAKER CONNECTIONS
+ ® - - © +
V- " _ J
Making the Speaker Connections
1. S trip %" of insulation from the speaker cable
and twist the stray ends together. If possible
solder the ends. Push the lever beneath the
terminal as shown in the diagram, and aligning
the inner and outer terminal holes. Then fully
insert the stripped wire. Release the lever, and
the wire end will be firmly clamped.
2. Use the upper (A) terminals first. Be careful
that the terminals identified by the + and —
signs above them are connected with the
corresponding + and — terminals on the
speakers. A mistake will result in poor bass
response and ill-defined stereo image. Also be
sure to connect the left-hand speaker to the L
speaker terminals, and the right-hand to the R
terminals.
3. Repeat this with the B terminals if other
speakers are to be connected. In ail cases make
sure that connections are fully and firmly
made, or you may not be able to get any sound
from one or more speakers.
®AC OUTLETS
These spare AC Outlets are provided for your
convenience in connecting other items of audio
equipment. Only the left outlet is controlled by
the CR-840 power switch. This has a maximum
power rating of 200 watts, and should be used for
items such as turntable units. Do not connect any
item which draws more than 200 watts. The other
outlets are not affected by the CR-840 power
switch, and any items connected to them must be
switched on and off by their own power switches.
Note that the total power available from these two
outlets together is only 200 watts. Use them for
such items as your tape deck.
0C5IMD (©round) Terminal
The ground terminal is provided for grounding
turntable units.
©INPUT Terminals
These are the terminals which are selected by the
Input Selector switch on the front panel. They
include Phono and Aux connections. The Aux
terminals can be used to connect an external
tuner, or for an 8-track cartridge tape player, etc.
§TAPE PB and RECOLJT Terminals
Two tape decks can be attached to these input and
output terminals. Recording can be made on both
tape decks at the same time, of any source
connected to the CR-840, by setting the Recout
selector switch on the front panel to the appropri¬
ate position. Tapes can be dubbed from one deck
to the other in either direction, and recording can
proceed while any other source selected by the
Input selector is being auditioned.
@ADAPTOH Terminals
When connecting a Graphic Equalizer, Dolby Unit
or any other audio equipment to the Adaptor
terminals connect its output terminal to the
FROM terminals of CR-840 and its input terminal
to the TO terminals of the CR-840.
©AC Electrical Power (Lane
Plug the CR-840 power cord into a main power
supply wall outlet socket, and make sure the line is
not likely to be tripped over.

The T-type antenna provided with yourCR-840 is
adequate only in high signal strength areas and
under favorable conditions. In other cases, an
external multi-element FM antenna is needed. If
you cannot obtain satisfactory reception with the
T-type antenna, this is an indication that you need
an external FM antenna. To ensure the very best
results, a motor-driven antenna assembly with
remote control of its orientation is ideal, but the
CR-840 has sufficient sensitivity to operate well
with a fixed antenna. The external antenna should
perferably be located fairly close to the CR-840,
and mounted as high as conveniently possible. Try
various antenna orientations, either pointing
towards the weakest station you intend to receive
or away from the major source of interference
(preferably both, although some compromise is
usually necessary in most locations). If the
antenna is intended for use with shielded coaxial
cable (which reduces losses and interference) use
the 7512 UNBAL terminals on the rear panel of the
CR-840, and connect the cable as shown.
Antennas intended for use with the 30012 BAL
terminals on the rear panel (which use feeder wire
similar to that of the internal antenna provided)
can also be used with coaxial cable if a matching
transformer is attached to the antenna. The use of
coaxial cable is advisable where the antenna must
be located some distance from the CR-840, or
where interference from automobile ignition, etc.,
is troublesome.
Attaching the coaxial cable to the accessory plug
(21
Net wire holder
( 1 )
Plug section
Inserting the core
(1) Remove the outer cover¬
ing of the coaxial cable
up to about 23 mm from
its tip, and then slip the
plug fastener over the
coaxial cable.
(2) Insert the coaxial cable
core into the hole special¬
ly prepared for the core
on the plug. Insert the
net wire holder.
(3) Finally, screw in the plug
fastener.
Fig. 1
FM BROADCAST RECEPTION
1. Set the INPUT SELECTOR to TUNER.
2. Set the TUNER push-button to FM.
3. Check that the FM indicator LEDs light at the
right-hand side of the dial.
4. All switches and knobs should be as shown in
the front-panel diagram.
5. Tune for maximum signal strength on the
SIGNAL QUALITY meter, ignoring any oscilla¬
tions of the indicating pointer position.
6. Now tune to bring the FM TUNING meter
pointer to its exact center. This is the optimum
tuning position: set it carefully.
7. Check that the FM stereo indicating LED lights
if you intend listening to a stereo rather than a
monaural broadcast.
When connecting the coaxial cable to the 75£2
UNBAL connector which is located on the rear
panel of the CR-840, first attach the cable to the
accessory plug as shown in the figure, and then
connect.
lO

Fig. 2
FM MUTING/OTS SWITCH
This push-button switch should normally be left in
the ON position. If pushed into the OFF position,
it will over-ride the OTS circuits, allowing full
manual tuning, but preventing the automatic
correction of slight mis-tuning and of drift due to
the influence of temperature and humidity. Switch
OFF for reception of weak stations near powerful
local stations which might be 'pulled in' by the
OTS. If you decide that the weakest stations
cannot give you sufficient listening enjoyment,
leave this control in the FM MUTING/OTS ON
position. The weakest stations will be cut out,
along with the interstation noise. You will be able
to tune from station to station, sure of good
quality reception, free of background noise and
remote, very poor quality stations.
Fig. 3
SIGNAL QUALITY METER
The SIGNAL QUALITY meter, as well as giving a
reading for the signal strength of AM and FM
station signals, also gives a visual indication of FM
signal quality. When so-called 'multipath' (waves
reflected from nearby hills or tall buildings) are
present, the meter pointer will oscillate, centering
on the average value of the signal strength.
If you notice such variations in the SIGNAL
QUALITY meter readings, try different antenna
orientations. You will generally enjoy better tonal
quality if you orient the antenna to give a steady
reading, even if this level is a little lower than the
maximum when the indication is fluctuating.
Fig. 4

MULTIPATH DETECTION
FM multipath is somewhat like the TV “ghost''
phenomenon. As shown in Fig. 5 , some FM
signals are received directly by the antenna while
others reach it from many directions, bouncing off
buildings or mountains. The latter are called
multipath waves. These are received slightly later
than the direct waves, and this causes some sound
distortion and deterioration in separation and
tonal quality. This multipath effect can be mini¬
mized by using a tall antenna with good direction¬
al characteristics and by careful orientation so as
to eliminate interference.
During FM reception, a delicate quiver of the
signal meter indicator indicates multipath inter¬
ference. Change your antenna orientation or posi¬
tion so that the indicator stabilizes.
Fig. 5
1 1

CONNECTING THE LOOP ANTE IVIN
Connect the cord from the loop antenna to the
ANTENNA AM and GND terminals on the rear
panel of the receiver. If the combination bar is not
removed, best reception will not be obtained.
Note: Always be sure to remove the combination bar
when connecting the loop antenna.
Always be sure to remove the loop antenna
_ when using the combination bar. _
Fig. 9
USING THE LOOP ANTENNA
Adjust the direction of the loop antenna for best
reception as shown in the Fig. 10.
Since the AM broadcast frequency band is a low
500 kHz ~ 1,600 kHz, its wavelength is approxi¬
mately 300m at 1,000 kHz and the use of a long
antenna is ideal for noise-free reception. However,
an FM antenna is actually used as an AM antenna
and AM broadcasts are received at an extremely
low input level.
Therefore, satisfactory reception may be impossi¬
ble where AM receiving conditions are poor (such
Conditions and Symptoms when receiving AM broadcasts with the Loop Antenna
Receiving Conditions
- What antenna are you using in what room?
Symptom
— What are the receiving conditions of
the AM broadcast you want to receive?
Room
Antenna
Inside Building
T-type FM antenna
AM broadcasts cannot be received.
Inside Building and near
Noise sources. &
T-type FM antenna
Very Noisy (Signal meter pointer
deflects only slightly.)
Not inside Building, but near
Noise sources. %
T-type FM antenna
(with lead wire extension)
Very Noisy (Signal meter pointer
deflects only slightly.)
In a room near a power line.
T-type FM antenna
Modulation hum is loud.
Near a high tension line.
Outdoor antenna or Community
antenna
Broadcast station signal is
strong, but antenna is near
indoor wiring and Noise
sources. &
T-type FM antenna, Outdoor
antenna, or Community antenna
Interference.
as inside a building and near fluorescent lamps,
thermostats, motors, or discharge lamps).
Use this loop antenna by referring to the following
table.
This loop antenna is designed to be used vertically.
If used otherwise, its reception sensitivity reduce
expensively. So, please do not fail to use it verti¬
cally all the time.
^ Noise sources: Fluorescent lamps, thermostats, motors, discharge lamps, and other electrical devices.
* Under the conditions except the above figure, use the combination bar.

AM RECEPTION
First set the TUNER FM/AM switch to AM, and
set the tuning indicator to the desired station
frequency. Adjust the tuning knob to give the
maximum SIGNAL meter reading. Note that the
FM TUNING meter does not function for AM
stations.
Your Yamaha Loop Antenna is a special, low-noise
antenna for AM broadcasts. Always be sure to
connect it to your receiver. Otherwise, AM
broadcasts may not received.
If the FM antenna is used for an AM antenna,
install the combination bar as in Fig. 9.
INSTALLATION
1. Installation position
This antenna can be mounted to the re^r panel
of a receiver, rear of a rack, or on a wall. Install
it as far away from noise sources as possible.
2. Installation method
Peel the seal off the rear of the antenna holder,
position the adhesive side of the holder at the
position you wish to install it, and push the
holder against the panel, wall, or rack firmly.
Note: Since the adhesive is extremely strong,
be sure to position the holder correctly
before mounting it securely.
The loop antenna can be detached from the
holder and reinstalled by either of the two
methods illustrated in the Fig. 8. Use the
method which provides the best reception.
Fig. 8

CONNECTING A TURNTABLE
The main AC supply plug of your turntable unit
may be inserted into the spare AC outlet socket
controlled by the CR-840 POWER switch.
With some turntables it is important not to dis¬
connect the main supply without first switching
off the turntable itself (read your turntable in¬
struction manual to check). In this case you
should use one of the two unswitched spare AC
outlets. The pin plugs on the output lead from the
turntable usit should be connected to the PHONO
terminal pin jacks at the left-hand side of the rear
panel. Check that the L and R pin plugs (for the
left and right channels) have been correctly insert¬
ed. Do not forget to connect the turntable ground
line to the GND terminal on the CR-840 rear panel.
Switch on the receiver POWER switch and set the
INPUT SELECTOR switch to PHONO. The
PHONO input circuit is intended for use with
standard moving magnet (MM), moving iron (Ml)
or induced magnet (IM) cartridges. Certain moving
coil (MC) cartridges can also be used, but some
have output levels too low for satisfactory per¬
formance without the use of a step-up transformer
or head amplifier. Note that the PHONO input
pin-plugs should never be connected or discon¬
nected while the POWER switch is ON.
Always switch off your speakers by switching the
SPEAKER switch to the OFF when raising or
lowering the cartridge stylus over the record to
prevent overloading and possible damage.
If you play monaural records, the signal-to-noise
ratio will be improved if you push the MODE
switch to the MONO position.
If you notice a low-pitched rumble when playing
records, cut this out with the LOW filter. Similarly
you can use the HIGH filter to reduce unpleasant
surface noise or record 'scratch'. Use the BASS
and TREBLE, controls to give the best tonal
balance, and use the LOUDNESS control rather
than the main VOLUME control to reduce listen¬
ing levels below your normal maximum.

CONTINUOUS LOUDNESS CONTROL
Set this to the FLAT position for listening at
normal maximum levels. The LOUDNESS com¬
pensation circuitry enables the same subjective
tonal balance to be retained at lower listening
levels as this control is turned down.
LOW AND HIGH FILTERS
Sharp 12 dB/octave (LOW) and 6 dB/oct (HIGH)
cut-offs and low distortion ensure minimum tonal
degradation in the important frequencies which
carry most of the musical signal. These filters
effectively remove sub-sonic rumble and high
frequency tape hiss or record surface noise.
COMPREHENSIVE TONE CONTROLS
The carefully chosen turnover frequencies of the
bass and treble tone controls have optimum
influence at the higher and lower frequencies for
major correction of tonal character. The FLAT
position for each control functions as a DEFEAT
position, with completely flat response.
The presence control, centered about 3 kHz,
readily adjusts for mid-range characteristics.

INDEPENDENT AUDITION AND
Do not confuse the REC OUT SELECTOR and
INPUT SELECTOR switches. The INPUT
SELECTOR switch decides which program source
you hear. The REC OUT SELECTOR switch
decides which one you record. Yamaha receivers
are at present unique in offering independent
choice of audition and recording. Thus you can
listen 1:o a record while tape recording direct from
the AM/FM tuner section, or while dubbing from
one tape recorder to another (set the INPUT
switch to F’HONO and the REC OUT to TUNER,
TAPE 1 > 2, or TAPE 2 > 1 positions). Alterna¬
tively, you can tape record a disc while listening to
a FM broadcast or a music tape played back on a
second tape deck (but be careful that you do not
infringe copyright laws by tape recording proprie¬
tary material). Just set the REC OUT switch to
PHONO and the INPUT switch to TUNER or
TAPE 1 (or 2), respectively.
15

TAPE DECK CpNNECTIONS/PLAYBACK
The output leads provided with the tape deck are
used to connect the tape deck LINE output
terminals to the TAPE PB terminals on the rear
panel of the CR-840. Use the TAPE 1 terminals
for your main tape deck. Use the TAPE 2 termi¬
nals for a second tape deck or as a spare pair. Set
the INPUT SELECTOR to TAPE 1 to play back
tapes (or to TAPE 2 if you are using the TAPE 2
terminals). Use the output level controls on the
tape deck or decks to adjust the playback level so
that there is no great change in volume level when
switching between TUNER and TAPE 1 or 2
terminals.
TAPE DECK CONNECTI6nS/RECORDING
The tape-deck leads provided are used to connect
the deck LINE input terminals to the REC OUT
terminals on the rear panel of the CR-840. Again,
your should use the TAPE 1 terminals for your
main tape deck, keeping the TAPE 2 terminals for
a second tape deck or as a spare pair.
Note that the INPUT SELECTOR switch setting
has no effect whatever upon the signal which will
be recorded via these TAPE terminals. The REC
OUT terminals' output signal is decided by the
Fig. 15
REC OUT selector switch. If you refer to the
description of the REC OUT function on the
previous page you will see that the recording of
any of the program sources connected to the
CR-840 is possible: just set the REC OUT switch
to TUNER, PHONO, or AUX, as you wish.
Recording of any of these sources can proceed
while that source, or any other, is selected for
audition by the INPUT SELECTOR switch.
Monitoring of the recording while it is in progress
can also be carried out if you are using a three
head deck designed for monitoring. Just set the
INPUT SELECTOR switch to the TAPE position
(1 or 2).
(Note: most cassette tape decks have only two
heads, and monitoring is impossible; most open
reel decks do have three heads, with one used for
monitoring.)
The level at which a tape recording is made is very
important: for full details of recording techniques
you should consult the instruction manual
provided with your tape deck. Adjustments in
level must be made with the input level controls
on the tape deck. Note that the signals from the
REC OUT terminals which are recorded by your a
tape deck are not influenced at all by settings of
the tone, filter, and volume controls, etc., on the
front panel of the CR-840, and all such tonal and
other adjustments must be made on playback. If
you record at too low a level you will notice a high
level of tape 'hiss' on playpack, and if the level is
too high, the peak volume levels will be distorted
and you may even have difficulty in erasing them
later.

APE TO TAPE DUBBING
For tape-to-tape dubbing, you will need two
decks. Make the connections to the PB and REC
OUT terminals for TAPE 1 and TAPE 2 as
explained above. If there is a difference in the
quality of the decks, the best results will often be
obtained if the better deck is used for the record¬
ing rather than for the playback. Check by making
brief recordings in both directions and comparing
the resulting quality of playback.
Check carefully that the L (left) and R (right)
channel pin-jacks have been correctly connected
before commencing to dub. To copy a tape from
the TAPE 1 to the TAPE 2 terminals, use the
TAPE 1 ► 2 setting on the REC OUT selector
switch. Similarly, to copy from the TAPE 2 to the
TAPE 1 terminals, use the TAPE 2 ► 1 setting. In
both cases you can compare the original recording
and the copy by switching the INPUT SELECTOR
between the TAPE 1 and TAPE 2 settings
(provided that you have decks which allow you to
monitor). Once you are satisfied that the recording
is proceeding satisfactorily, you can turn the
INPUT SELECTOR switch to any other program
source you wish to enjoy, and the recording will
not be affected. If one or both of the tape decks
are not provided with an automatic shut-off
function, you should watch carefully for the end
of the tape in order to prevent strain on the drive
mechanism and capstan assembly.
When using a Graphic Equalizer to equalize input
and recording program output, Dolby Unit, or any
other audio equipment, connect it as shown in the
figure below and set the ADAPTOR switch on the
front panel to ON.
17

AUDIO SECTION
Minimum RMS Output Power per Channel
65 Watts (4 ohms) from 20 to 20,000 Hz at no more than 0,02% Total Harmonic Distortion.
60 Watts (8 ohms) from 20 to 20,000 Hz at no more than 0.02% Total Harmonic Distortion.
Continuous RMS Power
75 Watts (4 £2)
(both channels driven, 1 kHz) 65 Watts (8 £2)
Input Sensitivity/Impedance
Phono
2.5 mV/47 k£2
Aux, Tape 1,2 120 mV/40 k£2
Maximum Input Levels
Phono
140 mV at 1 kHz
Output Level/Impedance
Rec Out terminals (Phono)
120 mV/220 £2( rated)
(Aux Tape)
120 mV/5 k£2
Frequency Response
Phono RIAA deviation 0.4 dB
Aux, Tape 1,2 to SP Out 20 Hz to 20 kHz ±0.3 dB
Tone Control Characteristics
Bass turnover frequency
350 Hz
Bass boost/cut
± 10 dB at 50 Hz
Presence center frequency
3 kHz
Presence boost/cut
±6 dB
Treble turnover frequency
3.5 kHz
Treble boost/cut
±10 dB at 20 kHz
Filters and Loudness Control Characteristics
Low 25 Hz (12 dB/octave)
High
8 kHz (6 dB/octave)
Loudness control
Level-related equalization
Signal-to-Noise Ratio (IHF-A Network)
Phono
Aux, Tape 1,2
Residual noise
94 dB (INPUT shorted)
100 dB
0.17 mV
Distortion 20 Hz to 20 kHz
Phono to Rec Out
Aux, Tape to Sp Out (8 £2)
0,02% IV output
0.01% at 30 W
Noise-Distortion Clearance Range (NDCR) for 0.1% into 8 £2 at 1 kHz
From 10 mW to 60 Watts with Vol -20 dB (Phono Input to SP out)
Power Bandwidth (IHF)
10 Hz to 40 kHz
Damping Factor (at 1 kHz)
Better than 40 into 8 £2
FM SECTION
Tuning Range
87.6 to 108 MHz
Usable Sensitivity
300 £2
75 Q
9.3 dBf/1.6 jUV
9.3 dBf/0.8 jjV
50 dB Quieting Sensitivity
Mono
Stereo
15.3 dBf (3.2 juV)
37.3 dBf (40 juV)
Image Response Ratio (98 MHz)
80 dB
IF Response Ratio (98 MHz)
100 dB
Spurious Response Ratio (98 MHz)
100 dB
AM Suppression Ratio (IHF)
60 dB
Capture Ratio
1.5 dB
Alternate Channel Selectivity
DX 82 dB (IHF)
LOCAL 48 dB (IHF)
Signal-to-Noise Ratio (at 65 dBf)
Mono
Stereo
84 dB (IHF)
80 dB (IHF)
18