Pioneer SX-950 User manual

AM/FM STEREO RECEIVER
SX-950
OPERATING INSTRUCTIONS
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CONTENTS
IMPORTANT—LINE
VOLTAGE
The
SX-950
is
provided
with
a
line
voltage
selector
[BppceLpt
Line
Voltage
00+
-
<0
oe
--
0
2
Eaportant-Line
Voltege.-
-
-
on
the
rear
panel
(Fig.
A).
This
is
normally
pre-set
to
220V,
so
before
using
for
the
first
time,
or
if
the
Stereo
System
Composition
........-++-
9
unit
is
to
be
used
in
a
different
area,
it
is
important
SK-950
Features
......-6--
serene
3
to
check
the
compatibility
of
the
selector
setting.
Connection
Diagram
......-.-------55
4
CHANGING
THE
LINE
VOLTAGE
SETTING
:
;
1.
Disconnect
the
A.C.
mains
cord.
Connections
.----
+--+
reer
errr
6
2.Use
a
Phillips
screwdriver
to
take
out
the
.
ati
VOLTAGE
SELECTOR
plug
locking
screw.
Antenna
and
Ground
Connections
.......
7
) ; ;
a
SARL
3.
Pull
out
the
VOLTAGE
SELECTOR
plug
from
Front
Panel
Facilities
.....-..-...--45:
8
the
socket.
.
4.
Rotate
the
plug
until
the
cutway
aligns
with
the
How
to
Operate
the
Receiver
.-..------.
ae
appropriate
line
voltage
marker
on
the
back
of
Tape
Deck
Operation
......-...0--55-
12
the
unit,
and
then
replace
it
in
the
socket.
5. Replace the locking screw,
Adaptor
Jacks
for
Increased
Versatility
...
14
Employing PRE OUT and
POWER IN Jacks ............0-+55 16
Conditions Frequently Mistaken for
Malfunction’ i. 3s .ciaas oe bees o beg AT
SCREW PLUG
Specifications
........0-
626
e
ee
ee
eee
18
LINE
VOLTAGE
een
ae
ens
ve
Seen
ee
J
4
SELECTOR
STEREO SYSTEM COMPOSITION
Tape Deck
@ Be sure to install reel clamps when using vertically.
® Always keep heads ciean.
2 Do not neglect recorded tape for long periods.
® Avoid magnetic fields. . Tat ao
——- Turntable
* Protect from vibrations and close dust cover whenever possible,
® Store records vertically and protect from dust and dirt.
Speaker System
Rear and side panels of jeft
and right speakers should have
the same surroundings.
{Piacing with rear panel against
a wall improves bass)
Install speakers so that vibra
tions are not transferred di-
rectly to the floor,
(Employ stands or concrete
blocks with bookshelf type
speakers)
Thick curtain shuts
out direct suntight, SUN
$X-950
(Keep
connecting
—
{
4
cords
as
short
as
possibie.}
: Tin
ea
Se Gif
; N\ — pete Absorbs sound and vibrations
Furniture materials can improve tone. : 7 i (Placing in front of speakers is also effective.)
Listening position slightly to the rear of the apex of an equilateral triangle formed with teft and right speakers
®
Do
not
place
equipment
in
locations
that
are
unlevel
or
subject
to
vibration.
®
Allow
for
good
rear
panel
ventilation
of
components;
avoid
humidity
and
dust.
®
Keep
equipment
away
from
radiators
or
other
heat
source.

SX-950 FEATURES
LATEST TECHNOLOGY FRONT END
Two
dual
gate
MOS
FETs
(field
effect
transistors),
RF
amplification
and
a
buffer
amplifier
between
the
local
oscillator
and
mixer
stages
exemplify
the
advanced
tech-
nology
built
into
the
FM
front
end.
Together
with
carefully
selected
circuit
components,
this
provides
outstanding
per-
formance
in
terms
of
sensitivity,
overload
resistance,
image
rejection
and
spurious
rejection.
In
all
of
its
specifications,
the
SX-950
FM
tuner
section
compares
favorably
with
the
most
respected
separate
component
type
tuners.
HIGH SELECTIVITY IF STAGES
Excellent capture ratio, stable operation and sharp selec-
tivity are assured by three ceramic filters in the IF stages
and IC fimiters. The filters never need realignment and
contribute to high reliability against aging and ambient.
temperature variations.
QUADRATURE DETECTOR AND PLL
MPX DEMODULATOR
A balanced bridge differential amplifier performs quad-
rature detection of the FM signal. Linearity is assured
throughout the frequency band, while distortion becomes
minimized. Clear and stable separation is provided by the
PLL
(phase
locked
loop)
multiplex
circuit
design.
REDUCED DISTORTION AM CIRCUIT
Careful engineering is also evident in the AM tuner circuit.
Automatic gain control in the RF and IF stages, together
with a 3-gang variable capacitor and IC circuitry deliver
improved image ratio, selectivity and frequency response,
plus reduced distortion.
HEAVY DUTY SPLIT POWER SUPPLY
The dual positive and negative power supply incorporates
extra large 22,000 uF electrolytic capacitors and possesses
plenty of reserve power. Protection and muting functions
are included to both safeguard equipment and eliminate
power on-off noise.
PRECISION RIAA PHONO EQUALIZER
Deviation from the RIAA standard is performed within
+£0.3dB, while the ability of the phono inputs to accept
relatively strong signal fevels without distortion (200
mV rms) results in a wide dynamic range.
HIGH RELIABILITY PROTECTION CIRCUIT
In the event of malfunction, valuable semiconductors and
speakers
are
protected
by
a
relay
electronic
protection
circuit that detects DC output voltage or impedance over-
load. This ciecuit also functions to reduce noise during
ON-OFF operation of the power supply.
— ee ee (OMICS
VERSATILE TONE CONTROLS PLUS TURN-
OVER SELECTORS
Active
NFB
type
bass
and
treble
control
circuits
provide
precise
and
stable
control
without
affecting
the
mid-range.
Turnover
frequency
selector
switches
determine
the
points
at
which
the
tone
controls
take
effect,
and
a
convenient
tone
on-off
switch
is
also
employed
to
allow
a
flat
frequency
response
to
be
obtained
at
any
time
regardless
of
tone
contro!
and
turnover
switch
settings.
This
is
useful
for
checking
the
effects
of
the
phono
cartridge,
speakers,
listening
room
acoustics,
etc.
on
the
spaciousness
of
the
sound.
DIRECT COUPLED POWER AMPLIFIER
The power amplifier of the SX-950, is a direct-coupled,
pure complementary parrallel push pull circuit, which uses
a differential amplifier at first stage. SX-950 delivers
Continuous power output of 85 watts" per chan-
nel min, RMS at 8 ohms from 20 Hz to 20,000 Hz
with no more than 0.1% total harmonic distortion.
Plently
of
power
is
available
for
rich
and
stable
stereo
reproduction.
IMPORTANT
ADDITIONAL
FEATURES
Two tape monitor circuits allow two stereo tape decks to
be used for recording, playback and tape duplication.
Microphone input on the front panel adds to versatility
and enjoyment.
The audio muting switch can be used to temporarily reduce ~
the volume by 20dB when changing records or tapes or for
other reasons, without continually adjusting the volume
control.
tndicator lamps provide clear indication of operating mode.
TASTEFUL STYLING COMPLEMENTS HIGH
PERFORMANCE
The exquisitely designed aluminum front panel is trimmed
with solid walnut. Control functions and layout also add
to both versatility and top grade components appearance.
In comvination with high quality source components and
speaker systems, a magnificent stereophonic music system
is composed for providing rich audio enjoyment.
* Measured pursant to Federal Trade Commission's Trade
Regulation rule on Power Output Claims for Amplifiers.
3

CONNECTION
DIAGRAM
TURNTABLE TURNTABLE
CARTRIDGE
TAPE PLAYER
QUTDOOR
FM ANTENNA
T-TYPE
FM ANTENNA
jel came
a
PRE/POWER AMP. ern
The bridge connecting plugs between PRE OUT a
POWER IN jacks should always be left in position (F
normal use. Hf they are disconnected or removed, no
sound will come from the speakers. Always be sure to
switch off the power supply before atternpting to
remove them.
For the applications of the PRE OUT and POWER
Jacks, please refer to the section on “EMPLOYING
PRE OUT AND POWER IN JACKS” on page 16.
oe
AM ANTENNA yee ates
(Indoor or Outdoor)
GND
SPEAKER
SYSTEMS
A

i aN
PE DECK
-reel, cassette)
TAPE DECK
{Open-reel, cassette) DOLBY NR ADAPTOR
4 CHANNEL DISCRETE
ou
FOR USE IN UNITED KINGDOM ONLY
CAUTION
240V
Mains supply voltage is factory adjusted at 240 volts.
WARNING
THIS APPARATUS MUST BE EARTHED
IMPORTANT
The wires in this mains lead are coloured in ac-
VOLTAGE CONNECT TO! cordance with the following code:
SELECTOR AC CORD | Green-and-Yellow: Earth
i Blue: Neutral
} Brown: Live
As the colours of the wires in the mains lead of this
apparatus may not correspond with the coloured
markings identifying the terminals in your plug
proceed as follows.
The wire which is coloured green-and-yellow must
be connected to the terminal in the plug which is
marked by the letter KE or by the safety earth
symbol —s or coloured green or green-and-yellow.
The wire which is coloured blue must be connected
to the terminal which is marked with the letter N
or coloured blue or black.
The wire which is coloured brown must be con-
nected to the terminal which is marked with the
letter L or coloured brown or red.
"
The
AC
Outlets
of
this
apparatus
have
been
re-
a
=
moved
from
this
apparatus
in
order
to
comply
with
IGHT
U.K.
Safety
Regulation.
Ensure
that
your
equip-
SPEAKER SYSTEMS B SPEAKER SYSTEMS C ment is connected correctly~ if you are in doubt,
consult a qualified electrician. =i
* The word “Dolby” is a trademark of Dolby Laboratories Inc. ie errs =

CONNECTIONS
SPEAKER
SYSTEM
CONNECTION
The
receiver
is
equipped
with
three
sets
of
speaker
terminals
(A,
B,
and
C).
Use
the
A
terminals
for
the
speakers
in
normal
use.
As
shown
in
Fig.
1,
the
upper
socket
(red)
is
the
positive
(+)
terminal,
and
the
lower
(black)
is
the
negative
(~)
terminal
in
each
case.
In
the
same
way,
the
speakers
have
positive
and
negative
polarity
(+
and
—
terminals).
Be
sure
to
connect
terminals
of
the
same
polarity
together
(+
to
+,
and
~
to
~).
NOTE
When
two
sets
of
speaker
systems
are
being
used
at
the
same
time
(A
+
B,
A
+
C,
or
B
+
C),
please
ensure
that
the
impedance
of
each
speaker
system
is
not
less
than
85.
if
speaker
systems
with
impedances
below
89
are
used,
the
receiver’s
protection
circuit
may
operate
to
prevent
sound
being
produced.
SPEAKER OUTPUT TERMINALS
RIGHT
CHANNEL
LEFT
CHANNEL
RIGHT SPEAKER
SYSTEM
LEFT SPEAKER
SYSTEM
Fig. 7
Speaker Lead Wire Preparation & Connection (Fig. 2)
1. Strip about 10mm (3/8 inch) of the insulation
from the end of the speaker lead wire.
2. 1f the conductor is stranded, twist the strands
together so they do not come loose.
8.
Depress
the
black
colored
lever
of
the
speaker
terminal
and
insert
the
speaker
minus
lead
wire
into
the
hole
above
the
lever.
Return
the
lever
to
its
former
position.
4. Push up the red colored lever of the speaker
terminal and insert the speaker plus lead wire
into the hole below the lever. Return the lever
to its former position.
Speaker lead-wire
p-10mm-— .
~ Remove insulation
from wire end.
Twist stranded wire.
lever
Jever
=
Speaker
lead
-wires
Fig.
2
TURNTABLE CONNECTIONS
The receiver is fitted with two sets of input Jacks,
PHONO 1 and PHONO 2, enabling two turntables
fitted with magnetic phono cartridges to be con-
nected.
® Connections between the turntable OUTPUT
terminals and the receiver PHONO input jacks
should be made as shown in Fig. 3, taking care
not to confuse L & R channels. If, as in Fig. 3,
the turntable is fitted with a ground lead or plug,
this should be connected to the receiver GND
terminal.
NOTES:
I, When using a turntable fitted with two tonearms, the
oulput leads for each of the tonearms should be eon-
nected to the respective PHONO input jacks (1 and 2).
2. When using a turntable fitted with a moving coil (MC)
phono cartridge, it is essential to use a special MC
matching transformer or head amplifier.
TURNTABLE
GROUND WIRE
y eee 7 ae
CARTRIOGE |
TAPE PLAYER —~
USE OF THE AUX INPUT JACKS
These are a set of spare input jacks, which can be
connected to a cartridge tape player, television
sound tuner, or other signal source. The upper of
the two jacks is the L (left) channel, and the
lower is the R (right) channel (Fig. 3).

i TOMI CI
ANTENNA AND GROUND CONNECTIONS
FM ANTENNA CONNECTIONS
For the best results you should use an outdoor-
type FM antenna, although the simple T-type
antenna supplied with the receiver may be used
satisfactorily in areas of high signal strength (for
instance, those very near to the FM station, or in
a house of all-wooden construction).
FM Outdoor Antenna
Normally, install antenna as follows.
e Connect antenna feeder wire to the 8002
antenna terminals of the SX-950 as shown in
Fig. 4,
® While listening to broadcasts, as described on
page 10, install the antenna and determine the
best location for optimum reception. Secure
antenna firmly.
Outdoor AM antenna Station direction
Outdoor FM antenna
{special antenna)
AM terminal
feeder
terminais
Fig.
4
NOTE:
Urban areas with heavy traffic, industrial zones, or loca-
tions near high voltage power lines may experience
interference even with a special FM antenna. In such cases
seek the advice of an audio dealer. It may be advisable
to employ 75Q coaxial cable to connect the antenna to
the S¥-950 75Q UNBAL connector.
752 UNBAL
Connector
ANTENNA p) y
TERMINAL !
752
Coaxial
cabie
Fig. 5
T-type Antenna
The accompanying T-type antenna can be used
where FM signals are strong. Connect it to the
antenna terminals as shown in Fig.6. While
listening to an FM station, spread the two arms
horizontally and determine its best orientation.
Secure it to a wall or ceiling. See FM Reception
on page 10.
Indoor
AM
antenna,
Station
direction
vinyl
insulated
wire
4
"
:
XN
Fasten
with tacks
Fig. 6
AM ANTENNA
Normally,
position
the
ferrite
bar
antenna
(Fig.
7)
for
best
reception
while
listening
to
an
AM
station
as
described
on
page
10.
AM Indoor Antenna
If reception is difficult with the bar antenna, an
indoor AM antenna can be erected with vinyl
insulated wire as shown in Fig. 6.
AM Outdoor Antenna
For optimum AM reception, an outdoor AM
antenna using vinyl insulated wire can be erected
as shown in Fig. 4.
AM ferrite bar antenna
Fig, 7
GROUND
For maximum safety and to eliminate noise, con-
nect the GND terminal to an earth ground if at
all possible. See Fig. 4.
|
:
|

ae
FRONT PANEL FACILITIES
SPEAKER BUTTONS
Three sets of speaker terminals, A, B, and C, are provided
on the rear panel, and the required speaker systems can
be selected by depressing the SPEAKERS buttons as
follaws:
Bictea Set aad wa Speaker systems A operate
Boe de Se teas Speaker systems B operate
C ..... 2... .. Speaker systems C operate
NOTES
1. When any two buitons (A+B. B+C, C+A) are depressed
simultaneously, the corresponding pairs of speaker
systems will come into operation. However, ti is not
possible io operate all three speaker systems at the
same lime, even though all the buttons are depressed.
. For private listening through headphones, return all
the SPEAKERS buttons to the OFF (undepressed)
posraen
PHONES OUTPUT JACK —.—..
Accepts stereo headphones.
POWER SWITCH eee
After turning this switch ON there is a delay of some 3
to 6 seconds, during which time the protection circuit
operates to eliminate unpleasant noise.
BASS CONTROL
Clockwise rotation gives stronger emphasis to the bass
range below the turnover frequency (which is selected by
the BASS TURNOVER switch), while counterclockwise
rotation reduces bass response.
BASS TURNOVER SWITCH
This selects the frequency below which the bass tone con-
tro] will begin to act. This “turnover” frequency can be
set at 400Hz or 200Hz, to match the characteristics of
the room, the program material, or your personal listening
preferences.
TONE SWITCH
In the OFF (up) position, this switch causes the ampli-
fier section to operate with a flat frequency response
regardless of the tone control setting.
TREBLE TURNOVER SWITCH-
This switch selects the frequency above which the treble
tone control will begin to act, This “turnover” frequency
can be set at 2,5kHz or SkHz, to match the characteristics
of
the
room,
the
program
material,
or
your
personal
listening preferences.
TREBLE CONTROL .W..
Clockwise ro.
to
Bis A
on gives stronger emphasis to the high
range
above
the
turnover
frequency
(selected
by
the
TREBLE TURNOVER switch), while counterclockwise
rotation reduces high-range response,
eer renee)
FM TUNING METER tn
With the SIGNAL meter needle deflected to the right,
make fine adjustment by centering the FM TUNING
meter needie (indicating optimum reception).
SIGNAL
METER----—~——~-
For AM and FM station tuning.
AM tuning: Tune for maximum deflection
SIGNAL meter needle to the right.
Both the SIGNAL and FM TUNING meters
(see FM TUNING METER)
SPEAKER SYSTEM INDICATOR
_FM STEREO INDICATOR
of the
FM tuning:
work together
Mewes y
=
LOW CUT FILTER SWITCH.—_____--------
When low-pitched rumble (from turntable motor or other
source) is obstrusive, set this switch to the 30Hz position
to provide 6dB/octave attenuation at frequencies he
30Hz. If no interference is experienced,
position.
set in the ugg
HIGH CUT FILTER SWITCH
When high frequency scratch noise (from worn records
or other source) is unpleasant, set this switch to the 6KHz
position to provide 6dB/octave attenuation at frequencies
above 6kHz. If there is no interference, set, in the up
position.
MPX NOISE FILTER BUT JON
Comparatively high frequency noise, incurred when fF
ceiving weak FM siereo signals, can be eliminated by
depressing this button to ON. In this case however, thet
will be some loss of stereo separation.

TUNING KNOB po FUNCTION SELECTOR BUTTONS
Select the station and tune for optimum reception by : To select the program source, push the buttons as follows:
observing the SIGNAL meter for AM stations, and both | AM. ne ces For AM broadcast reception.
SIGNAL and TUNING meters for FM stations. FEM uge ages oes For FM broadcast reception. The STE-
|
Hl
i
j
i
i
iT
H
REO indicator lights up when the broad-
cast isin stereo. -
PHONO 1... . To operate a turntable connected to the
PHONO 1 input jacks.
PHONO 2/MIC.As above for PHONO 2 jacks, or for
reproduction through a microphone con-
nected to the MIC jack on the front panel.
Note: when the microphone is plugged in
the turntable connected to the PHONO 2
jacks cannat be used.
AURA rsa igo For listening to an audio component (car-
tridge tape player, TV sound tuner, etc.)
connected to the AUX input jacks.
NOTE: Only one FUNCTION button should be de-
pressed at a time.
po MIC JACK
| Accepts a standard 6 ¢mm microphone plug.
po AUDIO MUTING SWITCH - 20dB
| Set to —20dB to attenuate the audio output by 20dB.
This convenient feature saves having to disturb the
VOLUME control, for example when answering the
telephone.
VOLUME CONTROL
i
Governs the level of sound outputs both from the speaker
systems and from headphones.
|
“LOUDNESS SWITCH
APE MONITOR (1,2) SWITCHES
fea tee With a tape deck connected to the TAPE 1 i | Set to ON when listening at low volume. The frequency
jacks (REC and PLAY), either playback or i | response of the human ear varies according to the listening
monitoring of a recording in progress are pos- | | volume, and the ON position compensates for hearing
) sible i response by emphasizing the bass and treble.
. - i
De ahs Hsin Same as in 1 above, with a tape deck connected H
“—-MODE SWITCH
Set to STEREO for normal stereo operation. When set to
MONO, left and right channe! signals will be mixed and
reproduced monophonically from both speaker systems.
to the TAPE 2 jacks (REC and PLAY).
-TAPE
DUPLICATE
SWITCH
_
Set
this
switch
in
the
ON
(down)
position
to
duplicate
_
Or
edit
a
recorded
tape
using
two
tape
decks.
oe BA LANCE CONTROL
Adjusts the balance between the sound volume from the
left and right speaker systems or headphones.
EM
MUTING
BUTTON
Leave
this
button
undepressed
(in
the
ON
position)
to
|
UPpress
unpleasant
interstation
noise
while
tuning
be-
ADAPTOR
SWITCH
‘Ween
stations.
Low-strength
signals
may
also
be
sup-
When
employing
adaptor
components,
such
as
a
graphic
Pressed
by
this
function,
so
to
pick
up a
weak
station
equalizer
adaptor or
Dolby
NR
adaptor,
set this ADAPT-
depress
this
button
to
the
OFF
position.
OR
switch
to
ON,

HOW TO OPERATE THE RECEIVER
PRIOR TO SWITCHING POWER ON
Before switching on the power, set the various con-
trols as follows:
Turn the MUTING switch OFF (up)
Set the TREBLE and BASS controls to the midway
positions (the “0” positions)
Turn the TAPE MONITOR and ADAPTOR
switches to OFF (up)
Set the VOLUME control to MIN
(fully anticlockwise)
Turn the MODE switch to
STEREO (up)
Set the BALANCE control to the midway position
FM RECEPTION
Bs
2.
Depress the FM selector button.
Set the FM MUTING OFF button to ON(un-
depressed). Note, however, that in areas of low
signal strength the signal may be suppressed.
in this case only, the FM MUTING OFF should
be depressed.
.
Select
the
station
by
means
of
the
TUNING
knob.
Best
reception
is
obtained
when
the
SIGNAL
meter
needle
deflects
to
the
extreme
right,
and
the
TUNING
meter
needle
is
exactly
in
the
center,
as
shown
in
Fig,
8, If
the
broadcast
is
stereophonic,
the
STEREO
indicator
lamp
will
come
on;
it
will
not
illumimate
for
monophonic
broadcasts.
.
Adjust
the
sound
level
by
means
of
the
VOL-
UME
control,
and
use
the
BASS
and
TREBLE
controls
to
give
the
required
tone
quality.
AM RECEPTION
1. Depress the AM selector button.
2. Turn the TUNING knob to select your station.
Best reception is obtained when the SIGNAL
meter needie deflects to the extreme right (Fig. 9)
8. Adjust the VOLUME, BASS and TREBLE con-
trols for the listening level and tone quality of
your preference.
NOTE:
If, when listening to either FM or AM broadcasts, listening
pleasure is seriously affected by poor sensitivity or strong
interference, refer to the section “ANTENNA AND
GROUND
CONNECTIONS,”
on
page
7
and
make
any
{
necessary changes
ee
TUMNG
AM Reception
Fig. 9