Akai CS-34 User manual

CASSETTE TAPE DECK
MODEL CS _ 34 D
ALSO APPLICABLE TO MODEL CS-34
CASSETTE TAPE RECORDER
SECTION 1 SERVICE MANUAL ..............-0 20 cece neces 3
SECTION 2. PARTS LIST ............. 2.0... cece ence ees 17

SECTION 1
SERVICE MANUAL
TABLE OF CONTENTS
SPECIFICATIONS ©. 35:4 Wisc. asees ego encased elegans ete oysea 30s Sata Nee Poe enare ed
DISMANTLING OF UNIT ....... 0... ccc eens
ARRANGEMENT OF PRINCIPAL PARTS «..........00 00s eee eee
MECHANISM ADJUSTMENTS ........... 2 ee cee cee cece neces
1. PAUSE LEVER ADJUSTMENT ......... 002 ccc cee cee eee eens
2. ADJUSTMENT OF GAP BETWEEN TAKE-UP REEL TABLE AND
TAKE-UP WHEEL AT PAUSE MODE ..........
. F.FWD SLIDE ADJUSTMENT ............ 00000. e cece ee eee
. RWD SLIDE ADJUSTMENT... 2... eee tenes
. REC. SLIDE ADJUSTMENT ... 2.0... 0c ccc ccc cee eee
. OPERATION SWITCH POSITION ADJUSTMENT ................
. MUTE SWITCH ADJUSTMENT ..... 0.02... cece ce eee eee
. TAKE-UP TORQUE AT VARIOUS MODES AND
TORQUE MEASURING METHOD.............
9. PINCH WHEEL PRESSURE MEASURING METHOD ..............
HEAD ADJUSTMENT ......... 0.0. c ccc cece cette eee t eens
AMPLIFIER ADJUSTMENTS ........... 00. c ec ce cee ee eee eee ees
DOLBY N.R. CIRCUIT ADJUSTMENT ............. 0. cece eee
. D.C. RESISTANCE OF VARIOUS COILS ............. 0.0. ee eee eee
CLASSIFICATION OF VARIOUS P.C. BOARDS ............ 020.0005
1. P.C. BOARD INTERCHANGEABILITY CHART ...............0..
2. COMPOSITE VIEWS OF COMPONENTS .......... 00.20 c eee ene
i —
on HM FF WY
Rgas
For basic adjustments, measuring methods, and operating principles, refer to GENERAL
OPERATING PRINCIPLES AND ADJUSTMENTS.

I. SPECIFICATIONS
An asterisk next to a figure indicates the minimum guaranteed performance.
TRACK SYSTEM
4 track 2 channel stereo system
TAPE SPEED E 1-7/8 ips. (4.75 cm/sec) +3%
WOW/FLUTTER Less than 0.13% WRMS
*Less than 0.28% RMS
TOTAL WOW/FLUTTER *Less than 0.35% RMS
FREQUENCY RESPONSE LOW NOISE TAPE
CHROME TAPE
40 to 13,000 Hz +3 dB
*40 to 12,000 Hz +3 dB
40 to 15,000 Hz +3 dB
DISTORTION FACTOR
L *40 to 13,000 Hz +3 dB
Less than 1.5%
TOTAL DISTORTION FACTOR
*Less than 3%, 1,000 Hz, “0” VU recording
SIGNAL TO NOISE RATIO
Better than 52 dB, 1,000 Hz, “0” VU recording
*Better than 48 dB
TOTAL SIGNAL TO NOISE RATIO *Better than 43 dB
RESIDUAL NOISE
if Less than 10 mV/8 ohm load (CS-34 only)
OUTPUT LINE OUTPUT 0.775V (0 dBm +1.5 dB) using a 333 Hz, “0” VU pre-recorded tape
DIN OUTPUT 0.55V (-3 dBm +1.5 dB) using a 333 Hz, “0” VU pre-recorded tape
HEADPHONE OUTPUT 30 mV/8 ohm using a 333 Hz, “0” VU pre-recorded tape
SPEAKER OUTPUT 2W/8 ohm each channel (CS-34 only)
INPUT/IMPEDANCE MIC INPUT More than 0.35 mV/4.7 k ohm
LINE INPUT More than 80 mV/510 k ohm
DIN INPUT More than 3 mV/25 k ohm
RECORDING/PLAYBACK LEVEL
0 dBm +2 dB, 1,000 Hz, “0’”’ VU recording
ERASE RATIO
Better than 70 dB
CROSS TALK Better than 25 dB, 1,000 Hz +3 VU recording
*Better than 65 dB
RECORDING BIAS FREQUENCY
BIAS LEAK
60 +5 kHz
Less than -45 VU with recording volume at position “6”.
een
RECORDING TIME
FAST FORWARD AND REWIND TIME
HEAD RECORDING/PLAYBACK HEAD
ERASE HEAD
90 min. using a C-90 cassette tape
Within 80 seconds using a C-90 cassette tape.
4 track 2 channel recording/playback head
Type: P4-303
Gap: 1 micron
Impedance: 1,050 ohm +25% at 1 kHz
D.C. Resistance: 110 ohm
2 track 1 channel erase head
Type: E4-100
Gap: 0.3mm
Impedance : 730 ohm +10% at 100 kHz
1 DOC. Resistance: 5.2 ohm
MOTOR
Mechanical Governor Type D.C. Motor
Type: MHT-5PS
Specified Voltage: 13.2V
Revolutions: 2,200 rpm
TRANSISTORS/F.E.T.
2SC1647 (R) (S) (E)
2SC1648 (R) (S) (E) (U)... 6
2SA628 (E) (F)
2SC458LG (C) (D)...... 4
2SC94SL (Q) (R) ..---- 2 2SK34 (D).. 6... eee eee 2
2SC1096 (K) (L) .....- 2
DIODES IN60........... 6 WZ-085 ......... 1
IN4001......... 8 W213 90 int areca 1
1S2473VE....... 8 WZ-192 1.2.04. 1
SR-103D ........ 1
10D05 .......... 4 (CS-34 only)
LC. LC-4032 ........ 2 (CS-34 only)
POWER REQUIREMENT
Universal Models: 110 to 240V A.C., 50/60 Hz
Japan Models: 100V A.C., 50/60 Hz
CSA Models: 120V AC., 60 Hz
CEE Models: 220V A.C., 50 Hz
BSI Models: 240V A.C., 50 Hz
POWER CONSUMPTION
CS-34D: 12W
CS-34: 25W

i
a
S0—0—_—0_._—0—
DIMENSIONS
378(W)
x
110(H)
x
225(D)
mm
(14.9
x
4.3"
x
8.9")
(includes
all
protruding
parts)
WEIGHT
CS-34D:
4.8
kg
(10.6
lbs.)
CS-34:
4.9
kg
(10.8
lbs.)
NOTES:
1.
Specifications
determined
with
Low
Noise
Tape
unless
otherwise
noted.
2.
Specifications
subject
to
change
without
notice.

Ii. DISMANTLING OF UNIT
In case of trouble, etc. necessitating disassembly, please disassemble in the order shown in photographs. Reassemble
in reverse order.
CONTROL KNOBS
VU PANEL
LID COVER
FRONT PANEL
WOOD FRAME LOWER COVER
ADJUSTMENT

lil. ARRANGEMENT OF PRINCIPAL PARTS
VU METER CASSETTE BASE D.C. MOTOR LAMP P.C, BOARD CG-5003
DOLBY N.R. SWITCH
LIMITER SWITCH
a
TAPE SELECTOR
INDEX COUNTER
LAMP P.C. BOARD
CJ-l038
PAUSE SWITCH
POWER SWITCH
HEADPHONE JACK MIC JACK
RECORDING MICRO SWITCH HEAD BLOCK PAUSE BUTTON EJECT BUTTON
KEYBOARD BLOCK
FLYWHEEL OPERATION SWITCH
POWER SWITCH
PRE, AMP. P.C. BOARD
Cw-5214 (2D)
MUTE SWITCH Post ea eto fe alow . - ; Sib ; AUTOMATIC STOP MECHANISM
POWER TRANSFORMER
D.C. MOTOR

IV. MECHANISM ADJUSTMENTS
PAUSE LEVER
PINCH WHEEL ARM
Fig. 1
WIND PULLEY
TAKE-UP REEL TABLE
: WIND PLATE SPRING
7 SUPPLY REEL TABLE
: 0.5mm
_-7: WIND PULLEY
" RwD
REAR SIDE
“S— RWD SLIDE STOP
Fig. 4
1. PAUSE LEVER ADJUSTMENT (See Fig. 1)
Bend the part of pause lever indicated by arrow in
Fig. 1 so that at playback mode, the gap between
the pinch wheel arm and pause lever is more than
0.5 mm.
2. ADJUSTMENT OF GAP BETWEEN
TAKE-UP REEL TABLE AND TAKE-UP
WHEEL AT PAUSE MODE (See Fig. 2)
Bend the take-up lever in the direction of the arrow
in Fig.2 so that when the machine is set to pause
mode from playback mode, the take-up wheel com-
pletely separates from take-up reel table pulley and
the gap width is from 0.3 to 0.5mm.
3. F.LFWD SLIDE ADJUSTMENT (See Fig. 3)
Adjust by bending the F.FWD Slide so that when the
F.FWD and STOP buttons are gently braked simulta-
neously, the wind pulley separates from the take-up
reel table and this gap width is 0.5mm.
TAKE-UP REEL TABLE PULLEY
TAKE-UP LEVER
0.3 to 0.5mm
TAKE -UP WHEEL
PAUSE SLIDE
Fig. 2
WIND PLATE SPRING
REAR SIDE
Fig. 3
OBTAIN PARALLELISM
BETWEEN ARROW MARK
WIND SPRING
Fig. 5
4. RWD SLIDE ADJUSTMENT (See Fig. 4)
Adjust by bending the Rewind Slide so that when
the RWD and STOP Buttons are gently braked
simultaneously, the wind pulley separates from the
Supply Reel table and this gap width is 0.5mm.
NOTE: In the event that by bending the F.Fwd and
Rwd Slides a 0.5mm gap on both cannot be
attained, check the wind spring for parallel-
ism.
If it is not parallel, remove and bend wind
spring by hand to obtain parallelism. (See
Fig. 5)

REC. SLIDE
REC, MICRO SWITCH
ADJUSTMENT POINT
Fig. 6
i SETTING SCREW
|__MUTE SWITH
REC. SLIDE
HEAD BASE
Fig. 8
5. REC. SLIDE ADJUSTMENT (See Fig. 6)
At Stop mode, bend adjustment point (phosphor
bronze plate) of Rec. Slide toward arrow. (Fig. 6)
When the Rec. Button is depressed, the phosphor
bronze plate must properly turn ON the Rec.
microswitch.
6. OPERATION SWITCH POSITION
ADJUSTMENT (See Fig. 7)
Loosen setting screw and move switch base in direc-
tion of arrow in Fig. 7 until when PLAYBACK,
F.FWD or RWD mode is effected, the wind slide
turns ON Operation Switch perfectly and fix setting
screw to maintain optimum condition.
7.MUTE SWITCH ADJUSTMENT (See Fig. 8)
Loosen setting screw, and move Mute Switch back
and front and set so that at Playback or Recording
mode, Head Base turns OFF the Mute Switch.
SETTING SCREW
WIND SLIDE
Fig. 7
| CASSETTE TORQUE METER
Ea ee CI
Fig. 9
:) SPRING SCALE
PINCH WHEEL PRESSURE
300250q
PINCH WHEEL ARM Fig. 10
8. TAKE-UP TORQUE AT VARIOUS MODES
AND TORQUE MEASURING METHOD
(See Fig. 9)
As shown in Fig. 9, set a cassette torque neter on
cassette base, and take a reading of the A inlication
at each respective mode.
Playback mode 50 + 10 gr-cm
F.FWD mode 80 gr-cm
RWD mode 80 gr-cm
NOTE: Take the torque meter indicatio value
+10 gr-cm as recorder Take-up torqu:.
9. PINCH WHEEL PRESSURE MEASURING
METHOD (See Fig- 10)
As shown in Fig.10, at playback mode, pess the
pinch wheel arm toward shaft with a spring sale, and
when the pinch wheel separates from the :apstan,
read the spring scale indication.

V. HEAD ADJUSTMENT
HEAD HEIGHT
ADJUSTMENT SPACERS TAPE
REC/RB HEAD
P4-303
AZIMUTH
ALIGNMENT NUT
Fig. 11
NOTES:
1) Clean heads prior to head adjustment.
2) Be careful not to use a magnetized driver or other
magnetized tools in the vicinity of the heads.
3) Use only new tape as level variation is likely to occur
when using old tape.
4) Demagnetized heads with head demagnetizer before
and after head adjustment.
5) As perfect head adjustments are vital to tape deck or
recorder performance, be sure that these adjustments
are carried out properly.
VI. AMPLIFIER ADJUSTMENTS
Adjustment Item aioe Tape Mod Aaiusimaett Result Remarks
Supply Signal Point
ee
Playback Level 333 Hz “0” VU VR-4 ig
Adjustment Test Tape Pu, 1 k(B) OF ieeem |
Recording Level Low Noise Blank Rec VR-3 Set Tape
Adjustment Tape, 1,000 Hz, and 20 k(B) 0+2 dBm Selector to
(Low Noise Tape) “Q”? VU recording Play | (CW-5214) LOW NOISE
ee Se S|
Low Noise Blank 10,000 Hz
Frequency Response Tape, 1,000 Hz, Rec VR-5 0+ 1.0 dB
Adjustment and 200 k(B) : :
(Low Noise Tape) 10,000 Hz, -20 VU Pla (CW-5214) in relation
al acai ene recording 4 to 1,000 Hz
Chart 1
NOTES: 1. Set Tape Selector to LOW NOISE
2. Set Dolby N.R. Switch to OFF position.
3. Use new tape
4. The letter b following an adjustment parts number indicates “right channel”