Pioneer CT-730 User manual

C)
rrloNeerl'
aa ORDER
NO.
ARP-I47-O
STEREOCASSETTE
TAPEDECK
cT-73cI
o This
servicemanualisapplicableto theKU,HE,HB,HPandDtypes,
o Cemanueld'instruction
serefdreaumodeder6glage.
enfangais.
. Este
manualdeserviciotratadelm6tododeajusteescritoenespafrol.
CONTENTS
14
to
18
1. SPECTF|CAT|ONS
.....
2. FRONTPANEL
FACILITIES
3. BLOCK
DIAGRAM
4. CIRCUITDESCRIPTIONS
5. DISASSEMBLY
......
6. PARTS
LOCATION
7. EXPLODEOVIEWS
ANDPARTSLIST
. .
PICINEEFI ELECTFICINIC CCIFIPCIF|ATION a-r, Mesu.o 1 cho.ne. Mesu.o-ku, rokyo.1s3. Jape.
PIC,NEEFI ELECTFIC,NICB IUAAI lNC. '1925 E. Dom,nguez St., Long E]each. Ca ronnra 9OB1O U.S.A.
PIC'NEEFI ELECTFIC'NIC IEUFIC'PEI N.v. Lu thagen Hsven 9, 2O3O Antwe.p, Betg,um
FIC'NEEFI ELECTFIG,NICA AUATF|ALIA PTY. LTEI. '178-184 Boundanv Fload. E!.aesde, V,cto.r6 3195, Ausr.atia
8. ELECTRICAL
PARTSLIST.
9. PACKING
10. P.C. BOARD
CONNECTION
DIAGRAM
11. SCHEMATICDIAGRAM
12. ADJUSTMENTS
....
REGLAGE
AJUSTE.
25
z6
2S
J5
37
44
51
MODELCT.T3OCOMES
IN FIVEVERSIONS
DISTINGUISHED
AS FOLLOWS:
Typ. Voltrg€ Remarka
KU 120Vonly U.S.A.model
HE 22OV and 24OV {Switchablel Europemodel
HB 22OVa^d 24OV
(Swirchable) United Kingdom model
HP 22OVa d 24OV
(Switchable) Australia
model
D12OV22OVand
24OV
(Switchable) Gengral export model
YZ @ [4AY
1982 Prinred in
Japan

1. SPECIFICATIONS
systems compact cassette,2-channelstereo
Heads ."Hard Permalloy,, recording/playback headx l
"Ferrite" erasing
head x 1
Motor . DC servomotor x 1
Wow and Flutter No more than 0.0S%
(WRMSI
FastWinding Time . Approximately 1OO
seconds(C-60 tape)
Frequency Response
-20d8 recording:
Normaltape 25 to IS,OOOHZ
(35 to 14,000H2
t3dB)
Chrome tape . 25 to 16,000H2
(35 to 15,000H2
13dB)
Metal tape . 26 to 17,OooHz
(35 to 16,000H2
r3dB)
Signal-to-Noise
Ratio
Dolby NR OFF . . . More than STdB
Dolby NR ON More than 67dB (over
SkHz)
HarmonicDistortion No more than 1.2%
(OdB)
Input
(Sensitivity/Maximum
allowable
input/lmpedance)
MIC(L,Rl . . . . . . . 0.3mV/57mV/10kO,6mmdiam.jack
(Reference
MIC impedance;
25OO to 1OkOl
LINE{INPUT) ..50mV/25Vl75k0
Output (
Referencetevel/Load impedancel
LINE(OUTPUT).... ....4SOmV/SOka
Subfunctions
o Dotby NR system
(ON/OFF) B type
. 3 position tape selector (NORM/CrO, /METAL)
o lC full logic
control
. Air damp eject function
o Full automatic stop mechanism
r REC muting function
o Music searchfunction
. Timer stand-by mechanism
. One-touch recording system
. LED levelmeter
o Auto function svstem
Miscellaneous
Power
Requirements
KUmodel;
AC120V,
60Hz
HE,
HB,Hp
modets;AC22OVl24OV
(switchabtel,50/60H2
Dmodet;
AC12OV
l22OVl240V
(switchabte).
50/6OHz
Power
Consumotion
KU,HE,HB,HPmodets. .......2SW
Dmodel ...21W
Dimensions . .420 (W)
x 101
(Hl
x 235
(D)
mm
16-9/16
(W)
x4 (Hl
x 9-t/4
(Dl
in
Weight(withoutpackage! ... 4.2kg(9
lb4ozl
Furnished
Parts
Operating instructions 1
Connection
cord with pin plugg . . . 2
NOTES:
1. ReferenceTapes: Normal & LH: DIN 4SE13/BLATT6 or
eoulv.
CrO" DtN 4Sb13/BLATTT (CrO"
) or
equiv.
2. Reference Recording Level: Meter OdB indicating levet (160
nwb/m magnetic level= Philips cassette
referencelevell
3. Reference
Signal:
333H2
4. Wow & Flutter: . JIS [3kHz, with accustic compensation
(weighted) rms valuet DIN [3,'tsOHz, with acoustic com-
pensation(weighted)
PEAK valuel;
DIN 45507
g. Frequency Response:o Measuredat -20d8 level, DOLBy NR
OFF, level
deviation
isr6dB without indication.
6. Signal to Noise Ratio: o Measured at the third harmonic
distortion 3% level,weighted
(
DlN 4551
3/B
LATTT).
7. Sensitivity: Input level (mV) required for reference recording
level
with input (REC)controls
setto maximum.
8. Maximum Allowable Input: While decreasing
settingsof input
(REC) level controls and increasinglevel at input jacks, this is
the maximum input level (mV) at the point where recording
amplifier output waveform becomesclipped.
9. Reference Output Level: Playback output level when meter
indicatesodB.
NOTE:
Specifications and the design subject to possible modificetions
without notice due to improvements
I
2^

2. FRONTPANELFACILITIES
r
o POWER
SWTTCH
When this switch is depresed, the power isturned on and the level
indicator '!-" lights. Depress the switch again to releaseit when
turning off the power to the deck.
O The muting circuit is actuated after the POWER switch has
been set to ON and there will be no operation for about 4
seconds.This isnot afailure
or malfunction.
o When the POWERswitch is set to the OFF position
while the
tape deck is operating, the deck's operation isreleased
and the
stop mode isestablished.
€)TIMER STARTSWITCH
This switch is used when an optional audio timer isemployed for
unattended recording or wake-up playback operations. Keep this
switch at the OFF position when the timer is not being used.
REC : Set to this position to set the tape deck automatically
to the recording mode at the time preset on the audio
timer and to start the recording of programs unattended,
for instance.
OFF : For when the timer isnot being
used.
PLAY : Set to this position to set the tape deck automatically to
the playback mode at the time preset on the audio timer
and to start the playback. The tape playback function can
be used to wake-up in the morning instead of an alarm
clock.
For detailed instructions on the use of this function, refer to
RECORDING
AND PLAYBACK USINGTHE AUDIO TTMER
on
page'10.
oEJECT
BUTTON
Depress this button to open the cassette holder. To close the
cassette
holeer, push the top back until it locks.
o Do not press
this button when the tape is in motion.
@cesserrE
DooR
oTAPE COUNTER
This counter shows the position of the tape using a three-digit
meter.
@coururEn
REsET
BUTToN
Depress this button to reset the tape counter display to "000".
€) LEVEL INDICATOR
These indicate the input level during recording and the output
levelduring playback.
@ p'-"-t
tNDlcAToR
This indicator lights during the playback or recording mode. When
the PAUSE switch is depressed and the PLAY/PAUSE or REC/
PAUSE mode isestablished,the indicator goes
off.
I m (Music
Search)
INDICATOR
This indicatorlightswhilethe music
searchswitchis keptin the
depressed
position.
@
ruusrc
SEARcHswrrcH
When this switch is depressed
and the >> {FF} or << (REW}
switch is depressed,the unrecorded blanks between the program
on the cassette tap€ are detected and the deck is automatically
setto the playback mode.
F

(D
openeilNc
swrrcHEs
>> lFFl : Depressthis switch to send the tape forward at
high speed (The tape will travel from left to
right).
<< IREWI : Depress this switch to rewind the tape at high
speed (The tape will travel from right to left).
- (STOPI : Oepress
this switch to stop the tape travel and to
release
the operating switches.
rt
@ DOLBY
NR SWTTCH
Depressthis switch to ON for recording with the built-in Dolby
Noise Reduction system and for playback of tapes which have
been recordadusing the Dolby Noise Reduction system.
For other tap€s.do not press
this switch.
@
rnee
sELEcr
swtrcHEs
This selector allows the bias and equalizer characteristics to be
selected during recording and equalizer characteristics during
playback in line with the type of tape you are using.
Normal tapo : Release
the bottom switch to the ,,out,. position
(INORM}.
Chrom tape : Depressthe bottom switch to the ,.in,, position
( - HIGH) and release the top switch to the
"out" Position ( r CrOz).
Metal tape : Depress both the top and bottom switches to
the "in" positions.
(E)
REC
LEVEL
coNTRoL
Usethis to adjust the levelof the input signals
from the MIC jacks
or rear panel LINE-lNPUT. Turning the control to the clockwise
increase the level.
(D
REC
SWTTCH
Depressthis switch to start tape recording. This switch will not
work when a cassette
isnot loaded or when the erasure
prevention
tabs of a loaded cassette have been broken off.
When this switch is depressedto th€ ON position, the REC and
lpLA? indicators will be illuminated.
(D
REC
MUTE
SWTTCH
Depressing this switch during recording makes it possible to
create an unrecorded blank on the cassette
tape only for the time
during which the switch is kept depressed.
This switch isusedfor
providing blanks of the required length between programs and
editing tapes so that they are easierto listen to and for creating
the unrecorded blanks which are required for operating the
MUSIC SEARCH facility.
o No signal are recorded when the switch is touched during
recording. Do not touch the switch unless
necessary.
o REC MUTE (O ) is display only but does not illuminate.
(D
PAUSE
SWITCH
Depress
this switch to stop the tape temporarily during recording
or playback. Depressthis switch again to allow the tape to con-
tinue to travel. When this switch is depressed
to the ON position,
the ll (PAUSE)indicator
will beilluminated.
. The tape does not stop during fast forward or rewind opera-
tions evenwhen the PAUSE switch isdepressed.
@
MtcJAcKs
Theseare the input jacks for microphone recording. plug the left
channel microphone into the L jack and the right channel micro-
phoneinto the R iack.
Theword "Dolby" and D0 aretrdemark of Dolby Laboratories
Licensing
Corporation.
NoiseReduction
Systemmanufactured
under
licensefrom Dobly
Laboratories
Licensing
Corporation.
DOLBY
NOISE
REDUCTION
SYSTEM
The tape hiss (noise in the high-frequency region) which is in-
herent to cassette tapes and which is heard when sound recorded
onto a tape is played back hasalways beenannoying.
This is particularly the case
when, for instance.during an orches-
tral piece high-rangppianissimo sections such as those created by
violins are heard. The Dolby noise reduction system wasdevoloped
to r€duce this noise. lt functions when the midrange and treble
parts where the tape hiss is noticeable are lower than the fixed
level by recording these parts at a higher level then the normal
recording level. During playback. however. the level isreducedby
an amount equivalent to its increse during playback.
o The DOLBY NR switch should always be set to ON when play-
ing back a tape which was recorded using the Dolby noise re-
duction system. The high frequency sound will not be heard
properly when a tape which was no recorded using the Dolby
system is played back with the DOLBY NR switch at ON.

3. BLOCK DIAGRAM
LINE
I
NPUT
REC/PBHead
rFLAT AMP
t_ 20d8
_l
CONTROLCIRCUIT
VR3OI
@
EOUALIZER
AMP
Function Switch
silol
BIASCIRCUIT
MPX FILTER
6b{
* Qeog
5

\
20 dB
DOLBY
NR
CIRCUIT
Rch
PLAY
+B
n
LINE
OUTPUT
)N
sr02
-
|
)FF
a
Dsrg
+
Bt
(t2.3V)
+
82
(
il.5v)
+B3
(
tO.8V)
+84
(
5V)
LINE _ MIC
ON _ OFF
lvoRM - HrGt{
CTOA - METAL
oN - q!!
ON - OFF
oN -oll
5604: PLAY
s605: PAUSE
5606: REC
5607: REC MUTE
s608: MUS|C
SEARCH
(MS)
s90l I TttrER
Srool : PowER
Q
to8
ON - OFF
ON _OFF
ON _ OFF
ON - OFF
ON - OFF
REC-OFF-PLAY
ON - OFF
StlOl r ERASE
PREVEIITO€'ECTOR
HOLE
-N9_r9!E
Thc undcrlrncd irdicatd thc sitch polrton.
.r
1
SWITCHES:
SlOl I INPUT SELECTOR
SI02 : DOLBY NR
SIO3 . TAPE SELEC'OR
SlO4 : TAPE SELECIOR
s@t I FF
5602 : REw
s603: sToP
{,
IC60l
Pin
@
RECAMP
POWER
SUPPLY
METERCIRCUIT
120V60Hz
22Ovl24OV
50/60H2
120V1220V
1240V
50/60H
KU:
HE,
HB,
HP:
D:
Auto Function
xt$_L f,uerar
-€n | {l
--dl L------<tl
?NORM CrO?
sro3-3 sro4-2
+83

4. CIRCUIT DESCRIPTIONS
4.1 PLAYBACK CIRCUIT
The signal from the playback head is amplified
by the Q10UQ102 2-stage direct-coupled ampli-
fier. In the NORM position, the playback equali-
zation (120ps) compensation is achieved by the
NF circuit between the Q102 collector and Q101
emitter. In the METAL and CrOz positions, Q104
is turned on, and the equalization characteristics
switched from 120ps to 70ps to compensate the
frequency response. The level of the EQ AMP
output is set by a variable resistor, and further
amplified by the Q105 flat amplifier before being
passed
through the MPX filter and applied to pin
2 of the Dolby IC.
This Dolby circuit consists of IC401 (HALL226),
and the Dolby ON/OFF switch is linked to the
MPX filter ON/OFF switch. When the Dolby
switch is OFF, the 19kHz filter is bypassed.
The Dolby circuit output appears at pin 8 of
IC401, and is passed to LINE OUTPUT via a
switchingIC (ICa02).
4.2 RECORDING
CIRCUIT
The input signal from the microphone jack is
arnplified by the microphone amplifier IC101, and
passedvia the MIC/LINE selector switch to the
INPUT volume control where the input level is
adjusted. This adjusted signal is passed
via IC102
to flat amplifier Q105. D101 andD102 in the stage
before IC102 form a protector circuit designed
to protect ICLO? from large input signals. The
signal amplified by the flat amplifier is pa.ssed
via
the MPX filter to pin 2 of the Dolby IC, the output
appearing at pin 8. The level of this output is
adjusted by variable resistor. Then after equaliza-
tion in the REC AMP (IC403) in accordance
to
the type of tape being used, the signal is passed
*,
to the recording head. +
B
4.3 CONTROL
CIRCUIT
The control circuit in this deck utilizes a one-
chip IC (PM9002A) which enablesfeather-touch
operations. In addition to mechanism control,
this IC also includes music search(MS), auto-stop,
and timer start functions. And due to the digital
counter frequency divider system employed in
timing settings for the mechanism control, all
operational timing discrepancies
have been elimi-
nated. The PM9002A pin layout is shown in
Fig. 4-3, the functional block diagram in Fig. 4-2,
and the output pin time charts during different
modes in Figs.4-5 and 4-6. For interrelations
between circuits, seethe block diagram on page b
andin Fig. 4-1.
OperationsduringEach
Mode
The mechanical operations effected by the
following circuit changesare described in the next
chapter(see
page
11).
1.When
the POWER
Switch is
Switched
ON
Then the POWER switch is switched on, * 5V is
applied to pin 1 (Vcc) of IC601. During the initial
period when pin 1 voltage is being increasedfrom
0V to 5V (approximately from 0.6V to 2.4V) the
IC's internal reset circuit is activated, putting the
IC into stop status which is maintained for about
four seconds.During this time, no changecan be
effected by pressing any of the other operation
control buttons.
>tA
t\
REC/PB head
Erase
head
s90
|
PLAY
OFF
------J pg6 s607
REC
MUTE
rc60r PM
9OO2
A
PA
USE
AR
REC REC
pt-Ay REc
STOP PAL'SE
REW BIAS
osc
FF
MS
TIMER REC
MUTE
SIGNAL
MS
PrNcH
tiUF,
REw "11&.
END
r F DETECT
TIME
Fig.
4-1 Control
systemblock
diagram

2. PlayMode
When the PLAY button is pressed,
the level of
pin 5 1Pf,AY) of IC601 is switched to ,,L" level,
and the level of pin 24 (PINCH SOL) to ..H,'
level. Q603 is turned on and the pinch roller
activated. In addition, IC60L pin 27 (LINE
MUTE) is opened 416ms after the PLAY button
is pressed,thereby releasing the line mute status
to enable play mode operations to commence.
3. Recording
Mode
When a cassettehalf with its erasure prevention
tabs intact is loaded in the deck, pin B (AR) of
IC601 is switched to '3H" level, thereby enabling
the deck to be switched to recording mode.
When the REC button is pressed, ICO01 pin 4
tnECl is changed to "L" level. pin 20 (nnd) is
also changedto "L" while pin 19 (REC) is open.
As a result, the REC indicator lights up and the
reed relay (RYl01) is switched off, thereby
switching the signal path to the recording circuit.
And the IC601 pin 24 (PINCH SOL) changed
to
('H" level, tape transport is commenced,.Pin 22
(BIAS OSC) is opened 52ms after the REC button
is pressed,thereby activating the bias oscillator.
Pin 27 (LINE MUTE) and pin 28 (REC MUTE)
are opened 416ms after the REC button is pressed,
thereby releasing the line mute and recording mute
statusto permit recording to start.
4. FastForward Mode
When the FF button is pressedIC601 pin 8
(TF) is changed to "L" level, followed by pin
26 (FF SOL) being changedto "H" level 416ms
later. Q601 is thus turned on, activating the FF
solenoid to start fast forward operation.
5. RewindMode
When the REW button is pressed, IC601 pin
7 (RED is changedto "L" level, followed by pin
25 (REW SOL) beingchanged
to "H" level416ms
later. Q602 is thus turned on, activating the REW
solenoid to start rewind operation.
6. Pause Mode
The pause mode in this deck is released by
pressing the PAUSE button. The pause mode is
not releasedby pressing the PLAY button during
play/pause mode, or the REC button during re-
cording/pause mode. Note, however, that pressing
the PLAY button during recording/pause mode
switchesthe deck to play/pausemode, and pressing
the REC button during play/pause mode switches
the deck to recording/pause
mode.
If the PAUSE button is pressed
during stop mode,
pin 2 (PAUSE) and pin 21 (PAUSE) of IC601 are
both changed
to "L" level,thereby lighting up the
PAUSE indicator. When both the PLAY and
\
\
(
PM9002
l
REC
OFF
PLAY
T
MS
NOISE
FILTER t
iT
EET
sr-6F
FLfY
TEE
PAUSE
AT
REC
MUTE -. \
LINETIUTE
FF SOL.
REW
SOL.
PINCH
SOL.
MS SOL.
BrAS
OSC
PAUSE
RET
REC
TIMER
STAND.BY
AUTO
STOPTIME
ENO
PULSE
NFB {I
vcc
plusE
an
ENO
PU
LSE
SIGNAL
IN
L c h >4\.-{
REC
pr-iT
sr6F
REW
FF
MS
FF SOL.
REW SOL.
PINCH
SOL
MS SOL.
TIMING
SENSE
TIMING
NOISE
FI
L.
S
IGN
AL
IN
GNO
Timing
clck OSC
&
divid!r
INPUT
KEY OUTPUT
l__
| | Aurol
I I sroPl
L_,. -
Fig.4-2 PM9002A
internal
blockdiagram Fig.
4-3 PM9002A
pin
layout

PAUSE buttons are pressed, IC601 pin 2L is
changed to ('L" level, and the PAUSE indicator
lights up. And since pin 27 (LINE MUTE) of
this IC is changedto 6'H" level, the signal
circuit is
muted. If the REC and PAUSE buttons are both
pressed,
IC601 pin 20 tn-Edl and pin Zf lFeUSny
are changed to "L" level, resulting in both the
REC and PAUSE indicators lighting up, and the
signal circuit being switched to recording circuit.
Furthermore, pin 27 is opened, permitting output
of the signal to LINE OUTPUI, but since pin 28
has been changed to "H" Ievel, recording mute
mode is maintained.
7. MS
Operation
When the FF or REW button is pressedwith
the MS button ON, tape transport is stopped at the
blank portion of tape between tunes, and then
recommenced in play mode. When the FF button
is pressedvrith the MS button ON, IC6
Ot pin 24
(PINCH SOL) is changed
to "H" level for 312ms.
The pinch solenoid is thereby activated and the
headbase
starts
to rise.
Pin 23 (MS SOL) of IC601
is changedto '3H" level 260ms after the FF button
is pressed,resulting in Q604 being turned on and
the MS solenoid being activated. Following com-
pletion of the "poler assist" operation, the head
base is thus moved to the MS position. The FF
solenoid is activated 416ms after the FF button is
pressed, resulting in fast forward tape travel.
During this action, a fast forward playback signal
is applied to pin 13 (SIGNAL IN) of IC601, and
if this signal is interrupted for about 84ms (cor-
responding to a portion of blank tape between
tunes) IC601 switches to playback mode auto-
matically. The above operation is much the same
when the REW button is pressedinstead of the
FF button.
8. Auto-stop Mode
A photo-intermpter output is applied to pin
16 (END PAUSE) of IC601 during tapetransport,
resulting in the capacitor connected to pin L7
(C318) being chargedup and discharged
repeated-
ly. The potential at pin 17 is thus kept below the
threshold voltage, and prevents activation of the
auto-stop mechanism.
When tape travel stops and the take-up reel stops
turning, the photo-interrupter output is no longer
applied to pin 16, and the potential on the ca-
pacitor connected to pin 17 (C318) continues to
increase until it exceeds the threshold voltage.
The IC is thus switched to stop mode, thereby
stopping tape mechanisms.
9. Timer StartOperation
Timer recording, timer playback and off modes
are attained by changing the potential of IC601
pin 18 (TIMER) to * Vcc, ground, and open
respectively.
When a cassettetape with erasure prevention tabs
intact isloaded, ffid the POWER switch is switched
ON with the TIMER switch (5901) in the TIMER
REC position, recording mode is started about
four seconds after the power comes on. If the
erasureprevention tabs have been removed, how-
ever,
the tape deck remainsin stop mode.
If the POWER switch is switched ON with the
TIMER switch in the TIMER PLAY position,
playback mode is started about four seconds
after the power line voltage is established.There is
no timer start operations when the TIMER switch
isleft in the OFF position
10. Auto-function Operations
o When
TapeDeck
is
Switched
toPlayback
Mode
When the CT-730 is switched to playback
mode pin 27 of PM9002A is changed to '3L"
level,and the Q606 collector to "H" level.Pin 20
of PM90O2A is alsochanged
to "H" level,resulting
in Q308 being turned off, followed by Q307 also
beingturned off and the collector being changed
to
('H" Ievel. The output of IC602 (414) thus be-
comes ('L" level and the output of IC602 (gl4)
6'H" level. Q608 is turned on, a negativepulse is
passed
to the amplifier component, and the ampli-
fier is automatically switched to tape mode.
o When
Amplifier
isSwitched
toTAPE
When the amplifier TAPE function selector is
switched, a negative output pulse is passed from
the amplifier's automatic switching terminal. This
pulse is differentiated by C604, resulting in pin 5
of PM90O2Abeing changed
to "L" level.
Playback
mode is thereby startedjust as
if the PLAY button
(5604) had been
pressed.
o WhenAmplifier
is
Switched
toPHONO
When any of the other amplifier function
selectors apart from TAPE (such as PHONO) is
pressed,a positive pulse output is obtained from
the amplifier's automatic switching terminal.
This pulse is differentiated by C603, resulting in
6'H" level being applied to IC602 (Ll4), and the
IC602 (214) output being changedto "H" level.
Q609 is thus turned on, resulting in the CT-730
being switched to stop mode, just asif the STOP
button (S603)had been
pressed.

o When
the
TapeDeck
isin Recording
Mode
While the tape deck is in recording mode, pin 20
of PM9002A is at "L" level yvith Q307 on. The
IC602 (414) output is thus at "H" level, and the
IC602 (314\output level at"L" level.
Hence,
when
a positive pulse is applied by C603, the TC6O2
(Ll4) output remains at "H" Ievel, preventing the
deck from beingswitched to stop mode.
That is, the tape deck recording mode is main-
tained when other function selectors on the am-
plifier arepressed.
Automatic
switching
( l : during recording mode
Fig.
4-4 Auto-function
operation
o TimingChart
Normal operation MS
:
OFF
1
a
a
---tlU L a:r
H qtq (H) 3/4
oFF tc602
t/4
L I rceoz ,h
PMgoo2A MUrE
\Key input
\ M"d"-
T"rrfi\
PLAY STOP FF STOP REIY STOP REC/PAUSE PAUSE STOP REC STOP PAUSE PAUSE PLAY PAUSE
trIrltLlrrot&u&*
STO
PPLAY STOP FF STOP REW STOP REC
STANO.B' REC STOP REC STO
PPAUSE
STOP STOP PLAY PAUSE
LINE MUTE
( Pin
27) ILt_ t_ I
L
RECMUTE
l Pin
28) t_ t_
L
REC
( Pin 20l LJ J
REC
( Pin l9)
HI I
B|AS OSC
( Pin 221
HJ J
PINCH SOL.
( Pin 24 1
H
FF SOL.
( Pin 26l
H
tJ
REW SOL.
l Pin ZsI
Hr
MS SOL.
1 Pin 231
H
PAUSE
l Pin 2t,
H
L
Fig.4-5 PM9002A
timechart
(When
MS
switch
isOFF)
t

Normal operation MS SW: ON
Fig.
4-6 PM9002A timechart
(When
MS
switch
is
ON)
Direct change
Gearleverreturn
spring
(E) Flywheel
Cam
gear
(D)
Gear
lever
(F)
Stopper
(G)
Operating
lever
(
t
l- 4.4 MECHANICAL OPERATIONS
PlaybackMode
The CT-730 makes use of the capstan torque
when shifting the headbase
during playback mode.
(Both the recording/playback and erase headsare
mounted on the headbase).
o Stop
Mode
(see
Fig.4-71
The head base shift mechanism during stop
mode is shown in Fig. 4-7. Operating lever (A)
presses
down towards cam (C) due to operating
lever spring (B). With cam (C) combined with cam
gear (D), clockwise torque is applied to this cam
gear. Solenoid P is inactive, and the hook of gear
lever (F) is kept against stopper (G) of cam gear
(D) by the cam gear return spring (E), thereby
keeping cam gear (D) stationary. The flywheel is
belt-driven by the capstan motor, and rotates
counterclockwise together with the capstan gear.
STOP REW FF STOP PLAY STOP REC STOP REC FF REC PAUSE
REVIEW
LINE
MUTE
( Pin 27
1
REC
MUTE
( Pin 28 I
BrAS OSC
( Pin ?2')
PINCH SOL,
( Pin 291
FF SOL.
( Pin 261
RE|V SOL.
( Pin 25)
M
S SOL.
( Pin 23)
PAUSE
Pin 2
Capstan
gear
il#,"
l*
Soleno
Fis.4-7 STOP
operation

SwitchtoPlaybackMode
from
Stop
Mode
(see
Fig.4€)
1. Solenoid P is activated O , ild the hook of
gear
lever(F) is released
from stopper (G) O .
2. Operating lever (A) is pressed
down onto cam
(C) by operating lever spring (B) O , carn
gear (D) rotates @ and engages capstan gear
(H)
o
Solenoid
P '"' lGt
Fig.4-8 STOP
-+ PLAY operation1
Switchto PlaybackModefrom StopMode
(see
Fig.4-9)
3. Cam gear (H) continues rotating due to
capstan gear (H) () , ffid cerm (C) pushes
operating lever (A) up O
4. After cam (C) passes the point of maximum
Iift, cam gear (D) disengages capstan gear
(H) @
Fig.
4-9 STOP
-+PLAYoperation
2
SwitchtoPlaybackMode
fromStop
Mode
(see
Fig.4-10)
5. Operating lever spring (B) forces operating
lever (A) to press against cam (C) Q) ,
thereby tending to continue the rotationary
motion of cam gear (D), but since stopper
(G) catches
the arm of gear lever (F) @ ,
cam gear (D) stops rotating and operating
lever (A) becomes stationary (playback
mode).
(B)
Fig.
4-10
STOP
-+PLAY
operation3
o Operationof Different
Parts
As can be seen in Fig. 4-10, ttre head base
drive pin of operating lever (A) risesduring play-
back mode. This pin forces the head base up
through the action of the HB drive spring. The
pinch compressor spring is also lifted at the same
time, forcing the pinch roller into close contact
with the capstan. Furthermore, the brake plate is
lifted to release the reel brake. Pressure is also
applied to the idler arm, resulting in the TU
idler transmitting drive gear rotation to the TU
reel base (the drive gear being belt-driven by the
capstan
motor). (see
Fig.4-11).
Drive
gear
TU reel
base
TU idler
Fig.
4-11 Generation
oftake-up
torque
(D)
-
,n,

Switchto Stop Mode
fromPlayback
Mode
(see
Fig.
4-121
1. When solenoid P is deactivated O , the arm
of gearlever (F) is disconnectedfrom stopper
(G) bV the action of gearlever retum spring
(E) (D
2. Operating lever spring (B) forces operating
lever (A) against cam (C) @ , resulting in
rotation of cam gear (D) @ and lowering
of the head base
drive pin @
3. Stopper (G) catches the hook of gear lever
(F), stopping the mechanism in the condition
shownin Fig. 4-7 (stop mode).
(B)
Fig.4-12
PLAY
-+STOPoperation
FastForward Operation
When solenoid F is activated, the drive arm is
moved to the right, and the drive gear on the arm
engages
the idler g€il, resulting in rotation of the
TU reel baseas shown in Fig. 4-LB(the drive gear
being belt-driven by the capstan motor). At the
sametime, the pin on the branch of the drive arm
pushes the brake plate up, thereby releasingthe
reelbrake.
Brake
shoe
Drive
gear
TU reel
base
Brake
plate
Drive
arm Drive
arm
bracket
pin
Rewind
Operation
When solenoid R is activated (see Fig. 4-14),
the drive arm is moved to the left, and the drive
gear on the arm engages
the supply reel gearresult-
ing in rotation of the supply reel base.
At the same
time, the pin at the tip of the drive arm pushesthe
brake plate up, thereby releasing
the reel brake.
Brake
plate
Brake
shoe
SofenoidR
I I Brakeshoe
Supplyreel
base
Brakeplate Drive
arm
Fig.
4-14
Rewind
operation
MS
Operation
(Music
Search)
MS operation involves combination with fast
forward and rewind operations similar to cue and
review operations. At the beginning of MS opera-
tion, power is applied to solenoid p, resulting in
the playback operation outlined in Figs. 4-8, 4-g
and 4-LO being effected in very short period of
time, the head basebeingtifted by capstan
torque.
During this period, power is also supplied to the
PMS solenoid. Although solenoid p is soon re-
leased,the PMS solenoid maintains the head base
through the stopper lever. Since this pMS solenoid
is designed to maintain only the head base,the
pinch roller and TU idler are released. This is
followed by power also being supplied to solenoid
F or solenoid R, resulting in cue or review opera-
tion respectively.
Note: If MS operation is started after fast forward or
rewind mode has aleady started, solenoid F or
solenoid R is released temporarily, and reactiuated
after a brief period of playbach mode (mechanically
speaking).
Brake
plate Solenoid
F
Fig.4-13
Fast
forward
operation

5. DISASSEMBLY
o
8
I
I
I
zI:
q.@)
I
I
I
Sub panelbase
Door assembly
Mechanism
assembly
F3
_t 0tl
laI|
$iL
R
(,
@
/-\
Fig.5-1 Disassembly

2.
3.
4.
Bonnet
andTape
Mechanism
1. Unscrew the four screws Q holding the Bon-
net on and remove the Bonnet by sliding it
toward the rear.
Unscrew the sub-panql screw @ and gently
pressdown on hook G) with a screwdriver so
the sub-panel
can be pulled loose.
Unscrew the two sub-panel base screws O
and remove the sub-panel base. The eject,
stand-by and power knobs can now be re-
moved.
Remove the REC VR knob and the two screws
below @ and gently press down on hook @
with a screwdriver so the front panel can be
pulled loose.
5. Unscrew the front panel base screws €l and
removethe front panel base.
6. Remove the mechanism assemblyby removing
the door assembly and unscrewing screws
@
7
. Remove the panel stay by unscrewing screws
O , removing the connecting plate and
unscrewingscrews @
Front
Panel
1. Remove the meter assembly by removing
rivet O
2. Remove the counter by unscrewing screw
0
3. Remove the control assembly by removing
rivets O
Panel
stay
Fig.5-2 Disassembly
of front panelpath

6. PARTS LOCATION
Front
PanelView
Knob
{DOLBY NR)
RAC-233
Knob
{Ejecrl
RAC-231
Subpan€l
RNL.478
Knob (Stand by)
RAC-234
Knob {Power)
RAC-232
Doorassembly
RXX-387
NO?tsr
. Ports without port number cannot be supplied.
. The A morh found on aome component parts irdicates the importonce of the
sdfety factor of the pdrt. Therefore, uhen replocing, be 6urc to use
parts of identicol
desEaotion.
. For your Parts Stock Control, the fast mouing items arc indicated uith the marhs
** and *.
T* GENERALLY MOWS FASTER THAN 1.
This clossificotion sholl be od.justedby each distributor becauseit depends on model
number, temperature, humidity, etc.
Eonnet
RNA.576
Front panel
RNL-472
Knob (Function)
RAC-239
MIC
jack
RNK-073
Knob
(MSl
RAC-235
Knob
B{Tape selector)
RAC-237
KnobA (Tape
selector)
RAC-236
Front panel base
RN L.464
Knob
(REC
VR)
RAA-368
FrontViewwith Front Panel Removed
Counter
RAW-182
Cassette
plat€
RAH.413
Erasehead
RPB.O85
{RP8-096}
DOLBY NR slaitchassembly
RCV-099
aa aaa
REC/PBhead
RPB.O91
lRPB-097)

TopViewwith Bonnet
Removed
A* Power
transtormer
RTT-287
{120V;
KU type}
RTI-286'l22OVl24OV;
HE, HB,HP
types)
RTf -2AA
l12OVl22OV
/240V, D type)
Main
assembly
RWX-625
{KU,
Dtypes}
RWX-626
lHE.
HB,HPtypes)
Motorassembly
RXM-076
A** Power
swirch i-J
Capstanbelt
RE8411
Plunger
solenoid
F
RXP.117
(RXp-l14, I KU
tYPe
iiir_l -r I HE,HB,HP,Dtypes
RSA-055
(KU typ€l
RSA-O47
(HE,
HB,HPtypesl
RSA-Os7
(Dtype)
A * Plunger sol€noid
R
ffil,t,tu,
r*' "*
|"f;;lit', , HE,
HB.HP.Dtvpes
RearPanelView
Terminal
(LlNEl
RK8-Ot
8
Foot assembly
REC-369
3.s0jack
RKN-071
RDG-022
(RDG-030)
RDG-036
RDG,O32
RDC-O29
RDG.O39
) KU typ€
HE type
HB type
HP type
D type

7. EXPLODED
VIEWS AND PARTS LIST
NOTES:
o Partswithout part number cannot be
supplied.
o The S marh found on some component parts indicates the importance of the
safety factor of the part. Therefore, when replacing, be sure to use parts of identical
designation.
o For your Parts Stoch Control, the fast moving items are indicated with the marks
** and *.
** GENERALLY MOVES F'ASTER THAN *.
This classification shallbe adjusted by eachdistributor because
it depends on model
number, temperature, humidity, etc.
Symbol & Description Mark No. Part No. Symbol & Description
Part
List
Mark No. Part No.
1. RN4-576
2.
3. RNL400
4.
5.
6. RAC-233
7.
8. RNH-136
9.
10. RBH-917
11. RAC-231
12. RAC-234
13. RNL-410
14. RNL-478
** 15. RXX-387
Bonnet
Connection plate
Door escutcheon
DOLBY switch assembly
Switch P.C.B. holder
Knob (DOLBY NR)
Timer switch assembly
Elect plate
Sub panelstay
Eject spring
Knob (eiect)
Knob (standby)
Sub panel base
Subpanel
Door assembly
Paper
Knob (REC VR)
Front panel
Front panil base
Knob (Function)
Earth spring
Nylon rivet
3x4.5
Meter assembly
Cassette
plate
Mechanismassembly
Counter belt
Sensorassembly
Counterholder
Counter
Control assembly
Lamp holder
Lamp
LED holder
LED
LED
Push
switch
Function switch
Knob (MS)
Volume assembly
Panel
stay
Mainassembly
(KU, D types)
Main
assembly
(HE,
HB, HPtypes)
3.5d jack
Terminal
(LINE)
MIC
jack
Push
switch assembly
Heat
sink
Connector assembly2P
Connector assembly6P
Knob A (Tapeselectorl
Knob B (Tapeselector)
Wier
nut
Power
transformer
(120V, KU type)
Power transformer
l22OVl24OV, HE, HB, HPtypesl
Power transformer
n2OV l22OV1240V,
D type)
Capacitor
(KU type)
Capacitor
(HE, HB, HPtypes)
Capacitor
(D type)
Power
switch (KU type)
Power
switch (HE, HB, HPtypes)
Power switch (D type)
Knob (Power)
Power
cord (KU type)
Power
cord (HE bypel
Power
cord (HB type)
Power
cbrd (HP type)
Power
cord (D type)
Strain
relief
Power
switch mounting plate
Mainchassis
Foot assembly
Bottom cover
Sliding
stopper
Bottom plate
Screw
Screw
Screvv
Screw'
Screw
Cushion
Screw
Screw
Screw
Screw
Screw
Screw
Serial
plate (KU type)
Resinousrivet
Capacitor
cover
(KU. HE,HB,
HP
types)
51.
* 52-1
* 52-2
* 52-3
53-1
53-2
53-3
** 54-1
** 54-2
** 54-3
55.
56-1
56-2
56-3
56-4
56-s
57.
58.
59.
60.
RKP-298
RAC-236
RAC-237
RTr-2a7
RTT.286
RTT-288
RCG-006
RCG-009
RCG-008
RSA-055
RSA.047
RSA-057
RAC-232
RDG-022
(RDG-030)
RDG-O36
RDG-032
RDG.O29
RDG.O39
REC-376
REC-369
REC-355
BMZ3OPO6OFZK
vc230P060FMc
BC230P060FMC
PMA26PO5OFMC
VP23OPOSOFZK
VP23OPO6OFMC
VBZ26P06OFMC
R84-026
BMZ3OPO6OFMC
AT24OPOSOFMC
PMA3OP06OFMC
REC-287
46.
47.
48.
49.
50.
A
A
A
A
A
A
ii,
t.
A
A
A
A
A
A
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
REE-O81
R44-368
RN
L-472
RNL464
RAC-239
RBH-925
RAH413
** 26. REB468
27.
28.
29. RAW-182
30. RWG-I35
31.
** 32. REL-094
33.
* 34. PR5724S
* 35. BG5724S
** 36.
*t 37.
38.
39.
40.
RSG-131
RSG-063
RAC-235
41. RWX-625
RWX.626
42. RKN-071
43. RKB-018
44. RKN-073
45. RSG-130
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
18

Mark No. Part No. Symbol & Description Mark No. Part No. Symbol & Description
A79. RKC-060
80-1 RSX-O4s
80-2 RKR-020
o ForHE,HB,HPtypes
o ForDWpe
Relay
terminal
(HE,
HB, HP
types)
Line voltageselector
(switchable
2 positions;
22OV
l24OV, HE, HB, HPtypes)
Line voltageselector
(switchable
3 positions;
12OV
l22OV l24OV
, D type )
81 VCZ30P080FMC
82. VBZ30P080FMC
83. PMZ30P060FMC
84-1 REK-064
84-2 REK-O48
Schrew
(HE, HB, HP
types)
Screw
(HE, HB, Hp types)
Screw
Fuse 80OmA
(HE,
HB,
HP
rypes)
Fuse
0.5A (D type)
A**
A**
52-2
54-2

3
2
J
A
1
Exterior
(For
KUtype)
h.^?1
N
B
t3
14k
J<.t
oo
'l 0lt
I lS.Jrlthll
lil'["'Ql
Inl
l\te
q.
68
CA
r
65
66
D
3
2
1
N
".oN
-o
65
68
\5
\
N