Teac A-450 User manual

GENERAL INTRODUCTON
This
Service
Manual
is
provided
to
assist
service
technicians
throughout
the
world
to
properly
adjust,
repair
and
maintain
the
TEAC
A-450
Stereo
Cassette
Deck.
The
A-450
is
designed
to
be
used
with
a
high
quality
stereo
amplifier
system.
It
contains
many
of
the
standard
TEAC
features
such
as
selectable
BIAS
and
EQ,
DIN, MIC,
LINE
Inputs,
PAUSE
Control,
Auto-End-Stop,
PEAK
LEVEL
Indicator,
Large
VU
Meters,
TAPE
RUN
Indicator,
etc.
In
addition
it
has
Dolby
NR
Circuitry,
DOLBY
FM/COPY
Facility,
FM
MPX
Filter,
MIC/LINE
Mixing,
Outer-rotor
Motor
and
unexcelled
Wow
and
Flutter
Specs.
If
adjustments
or
repairs
are
too
complicated
and
are
difficult
for
you
to
accomplish,
or
if
you
have
any
technical
questions,
please
contact
the
nearest
TEAC
Factory
Service
Department
or
write
directly
to
a
TEAC
office,
the
addresses
of
which
are
written
on
the back
cover.
This
manual
is
written
specifically
for
the
A-450
Model
distributed
in
the
U.S.A.
and
Canada.
However,
the
differences
in
models
distributed
elsewhere
is
very
small.
See
the chart
on
page
30
for
a
comparison
of
the
various
models.
NOTE
When
ordering
replacement
parts,
please
refer
to
the
PARTS
LIST
which
is
printed
separately
from
this
manual.
_)
*
Noise
reduction
circuit
made
under
license
from
Dolby
Laboratories
Inc.
The
word
“Dolby”
and
the
Double-D
symbol
are
trademarks
of
Dolby
Laboratories
Inc.
TEAC CORPORATION‘
51031682

CONTENTS
Specifications & Service Data .............. 3
Test Equipment Required ................ 4
TEAC Test Tape .............. 4
Partial Dis-assembly of Main Parts............ 5
3-1. Case/Front Panel .............. 6
3-2. MOtOL oie cece ee ee eae ew eee 6
3-3. Cassette Holder. ............6.-- 7
3-4. Head/Pinch Roller .............. 7
0 Vena (-1:\¢ a em 7
3-4B. Pinch Roller.................- 7
3-5. Brake Bracket .............06- 8
3-6. Capstan Drive Ass’y/Drive Belt. ..... 8
3-7. Reel Table: icscce ve ve ae eee Sate 9
3-8. Fast Wind Roller Ass’y .......... 10
3-9, Power Transformer ............ 10
3-10. Play Idler Assy .............2.- 11
Mechanical Checks and Adjustments .......... 11
41. Pinch Roller Pressure .........-.. 11
42. Take-Up Torque .............. 12
43. Fast Forward Torque ............ 12
44. Rewind Torque .............-..- 13
Torque Measurement using
The Cassette Torque Meter ........ 13
4-5. Brake Tension .............00- 13
4-6. Tape Speed/Wow and Flutter ...... 14
4-6-1. Tape Speed ..............04.8.- 14
46-2. Wowand Flutter .............. 14
Parts Location 2.1.0.0... cece eee ee ee eee 15
Lubrication «2.0.2.0... eee ee ee eee 16
61. MOtOf rei gee lot Ae oe area eRe 16
62. Capstan Assy ........20e ee eee 16
6-3. Flywheel Ass’y ............606- 16
Electrical Checks and Adjustments .......... 16
7-1. Playback Performance .......... 17
7-1-1. | Record/Playback Head
Azimuth Adjustments ..........
7-1-2. Specified Output Level Setting......
7-1-3. VU Meter Calibration -Playback- ...
7-1-4. | Frequency Response -Playback-
7-1-5. Signal to Noise Ratio -Playback- ....
7-1-6. Headphone Output Level Checks ....
7-2. Monitor Performance ............
7-2-1. Minimum Input Level Checks ......
7-2-2. Specified LINE Control Setting
7-2-3. DOLBY FM/COPY CAL
Control Setting ................
7-2-4, VU Meter Calibration -Record-......
7-2-5. LED Peak Level Indicator
Calibration ..............000-
7-2-6. Dolby NR Effect Measurement
7-2-7. Dolby FM Compensator
Efficiency Checks ............-.
7-3. Recording Performance ..........
7-3-1. Bias Trap Adjustments ..........
7-3-2. Record Bias Setting ............
7-3-3. Record Level Setting ............
7-3-4. Distortion Checks ...........-..
7-3-5. Frequency Response -Overall- ......
7-3-6. Signal to Noise Ratio -Overall-......
7-3-7. Erase Efficiency ..............
7-3-8. Channel Separation ............
7-3-9. Adjacent Track Crosstalk Measurement
7-4. Adjustment Location ............
8. Level Diagram ......... 0... eee eee eee
9. Trouble-Shooting ........... 0... eee eee
10. Model Differences Comparison Chart ........
10-1. Functional Difference Table ......
10-2. Electrical Alignment Section ......
10-3. Frequency & Voltage Conversion ...
26
262mm (10 546)
ES
i}
410mm(16 ¥g')
445mm (17 2’)
176 mm(6 jg) —4
LTT TTT ty Ea ona co
SISAL
M-O13-1
Fig. 1-1 A-450 Dimensions

1.
SPECIFICATIONS
&
SERVICE
DATA
SPECIFICATIONS
Track System
Heads
Type of Tape
Tape Speed
Inputs
(level and impedance)
Outputs
(level and impedance)
Equalization
Head Configuration
Motor
Bias Frequency
Operating Position
Power Requirements
Power Consumption
Weight
* Pursuant to DIN Standards
SERVICE DATA
Mechanical
Tape Speed Deviation
Wow and Flutter
Pinch Roller Pressure
Reel Torque
Fast Winding Time
End-stop Activate Time
Electrical
Frequency Response
Signal to Noise Ratio
Erase Efficiency
Channel Separation
Crosstalk between
Adjacent Tracks
Total Harmonic Distortion
4-track, 2-channel stereo
Two: Erase and Record/Playback
Cassette
tape,
C-60
and
C-90
(Philips
type)
4.8 cm/s (1-7/8 ips)
Microphones:
Min.
input
level:
-67
dB
#2
dB
(10
Kohms
or
more)
Line:
Specified
input
level:
-5
dB
(50
Kohms)
Min. input level: —15 dB #2 dB
DIN*: Min. input level: -35 dB +2 dB
DOLBY FM/COPY: —15 dB +2 dB
Line
out:
Max.
output
level:
—3.5
dB
+1
dB
(50
Kohms)
Specified output level: —5 dB
Headphones:
Specified
output
level:
—21
dB
+2
dB
(8
ohms)
EQ 1: 3180 us + 70 us (for CrO, tape)
EQ2: 3180 us + 70 us (for FeCr tape)
EQ 3: 3180 ws + 120 us (for regular Hi-Fi tape)
1/2-track, 1-channel Erase Head
1/4-track, 2-channel Record/Playback Head
Hysteresis synchronous outer-rotor motor
100 kHz
Horizontal
117V
AC,
60
Hz(U.S.A./Canada
Models)
100/117/220/240V
AC,
50/60
Hz
(General
Export
Models)
220V AC, 50 Hz (Europe Models)
18 W
9.5 kg (21 Ibs) net
3,000 Hz +30 Hz
Playback: 0.07% (WRMS)
Record/Playback:
0.10%
(WRMS)
400 g420 g (13.5 ~ 15.0 02)
Take
Up:
40
~70
g-cm
(0.6
~
1.0
oz-inch)
Fast
Forward:
100
g-cm
(1.4
oz-inch)
or
more
Rewind:
100
g-cm
(1.4
oz:inch)
or
more
100 seconds for C-60
4 seconds+2 sec.
Refer
to
frequency
response
limits
charts
on
page
18
and
24.
Playback
method:
47
dB
minimum
Record/Playback
method:
BIAS/EQ
1:
47
dB
minimum
BIAS/EQ
2,
3:
45
dB
minimum
With
Dolby
Noise
Reduction
used
for
recording
and
playback,
S/N
ratio
is
improved
by
5
dB
at
1
kHz
and
10
dB
at
frequencies
over
5
kHz.
65
dB
minimum
30
dB
minimum
(at
1
kHz)
40
dB
minimum
(at
125
Hz)
BIAS/EQ 1: 2.5% (maximum)
BIAS/EQ 2: 2.5% (maximum)
BIAS/EQ 3: 2.5% (maximum)
NOTE:
©
Improvements
may
result
in
Specifications
and
Service
Data
changes.
e
Value
of
“dB”
in
the
Data
refer
to
0
dB
=
0.775V,
except
where
specified.
If
a
Test
Set
or
VTVM
calibrated
to
0
dB
=
1V
is
to
be
used,
appropriate
comprensation
should
be
made.

2. TEST EQUIPMENT REQUIRED
1. Spring scale: For take-up torque check:
For fast forward & rewind torque checks:
2. String: Length: about 50 cm (20)
3. Cassette Reel Adapter: Diameter: 22 mm
* The tools above (1 — 3) are constructed as shown in Fig. 2-2.
O-—70g (O—2.50z.)
0 — 200 g (0 — 7.0 oz.)
4, Cassette Torque Meter: For take-up torque check: 0 — 100 g*cm (0 — 1.4 oz. inch)
For fast forward & rewind torque checks: 0— 160 g*cm (0 — 2.2 oz. inch)
* Use of the Cassette Torque Meter instead of the spring scale, if you have one, is recommended for
easier measuring. (See Fig. 4-6 on page 13)
* When ordering Cassette Torque Meter, allow for longer delivery time that is required for it.
5. Spring scale: For Pinch Roller pressure check: 0— 1 kg (2.2 lbs)
6. Wow/flutter meter: MEGURO DENPA SOKKI K.K., Model MK-668A
7. Frequency counter: Digital type, capable of 10 Hz to 100 kHz indication.
8. AF oscillator: 10 Hz — 100 kHz
9, AC VTVM: 0.1 mV — 300 V
10. Attenuator: General Purpose
11. Distortion analyzer; Basic frequency 400 Hz/1 kHz
12. Oscilloscope: General Purpose
13. Band-pass filter: 1 kHz narrow band-pass type
14. Test load resistor: Non inductive type 8 ohm/1 W
15. Plastic alignment tool:
16. Head demagnetizer; TEAC E-1 or equivalent
17. Cleaner: TEAC TZ-261 Tape Recorder Cleaner kit or pure alcohol
18. Oil: TEAC TZ-255 Oil kit or equivalent
TEAC TEST TAPE
For tape speed & wow/flutter test
MTT-111:
MTT-502:
For playback performance alignment
* For Dolby level Calibration
MTT-150:
MTT-116K:
MTT116U:
* For Playback method
* 3,000 Hz/—10 dB
‘For Record/playback method (blank
tape)
REMARKS: 0 dB = DIN Reference Level (333 Hz)
For record performance alignment (blank tape)
MTT-505TB: For BIAS 1/EQ 1 (CrO,)
MTT-504T: For BIAS 2/EQ 2 (Fe-Cr)
MTT-501: For BIAS 3/EQ 3 (Hi-Fi tape)
NOTE: The TEAC test tapes require longer delivery
time.
* Dolby B-type tone (modulated 400 Hz
tone), 200 nWb/m
*For frequency response test for EQ1&
2(CrO, & Fe-Cr)
* 3180 us + 7Ous
*315 Hz/-4 dB, 31.5 Hz — 14 kHz/-24
dB
*For frequency response test for EQ 3
(Hi-Fi tape)
* 3180 ws + 120 ps
*315 Hz/-4 dB, 31.5 Hz — 14 kHz/-24
dB
Fig. 2-1 TEAC Test Tape

iff
Fig.
2-2
Spring
Scale
&
Cassette
Reel
Adapter
Fig.
2-3
Plastic
Alignment
Tool
TEAC Tz-261
TAPE RECORDER
i CLEANER
Fig.
2-4
E-1
Head
Demagnetizer
Fig.
2-5
TZ-261
Tape
Recorder
Cleaner
Kit
Fig.
2-6
TZ-255
Oil
Kit
3.
PARTIAL
DIS-ASSEMBLY
OF
MAIN
PARTS
NOTE
1.
Use
the
proper
tools.
Demagnetize
the
tools
before
use.
When
mounting
or
removing
a
spring,
pay
heed
to
the
position
(direction)
of
the
anchor
or
hook.
The
wrong
position
may
result
in
a
change
in
the
tension.
3.
When
reassembling,
don’t
forget
to
reinstall
all
hardware
such
as
springs
and
washers,
etc.
4.
For
assembling
hardware
shape
identification,
see
ASSEMBL-
ING
HARDWARE
CODING
LIST
on
the
Parts
List.

3-1.
Remove the parts in the following
sequence.
1.
NDARWH
When removing or installing the Front
Panel, set the BIAS/EQ Switches to
the
the
easier.
3-2.
i
2.
3.
CASE/FRONT PANEL
Left and right Sideboards (C and
E)
Head Cover (B)
Cassette Storage Tray (A)
Trim Case Cover (D)
Bottom Cover (H)
Six Knobs (G)
Front Panel (F)
2 position and other switches to
upper position to make work
MOTOR
Remove the Trim Case Cover. See the above section.
Release the Drive Belt from the Motor Pulley.
Unsolder the 3 wires of the Motor Ass’y from the
2L-5P terminal strip located inside of the main chassis.
Note the color code and the position of each wire prior
to unsoldering the Motor leads.
Lift the Motor Ass’y out of the chassis.
NOTE
When re-assembling, clean the pulley and the Belt
with TEAC TZ-261 Cleaner kit (“‘A” for the
Pulley, “B” for the Belt) or with pure alcohol.
Take off or remount the Motor Ass’y taking care
not to scratch or otherwise damage the Motor
Pulley.
When re-attaching the Drive Belt to the Pulley do
not twist or stretch the belt.
3-B _M3x6
ied
=
SS
P
3-BM26x6
.
2-B M26xl2 ZS e
B SES >
@ K SP J ] S
Fig. 3-2 Motor Replacement

3-3.
CASSETTE
HOLDER
1.
Remove
the
Trim
Case
Cover.
See
2-PSA
M26x4
3-1
Section
on
page
6.
om
2.
Loosen
the
screw
(G)
and
then
C
0.9
-
ARR
artially
turn
the
Stopper
Bracket
:
G
-
partially
pp
c-3
Ba
kes
(H) in the direction of the arrow
to enable the Cassette Holder (D)
to be readily removed.
3. Remove the Spring (E) from the
hook (C) of the Cassette Holder.
4. Remove the other end of the
Spring (E) from the Lever (F) to
retain it.
5. Remove the Cassette Holder Shaft
(A) by taking off the 2 E-rings to
separate the Cassette Holder from
the Cassette Holder Retainer (B).
6. Remove the Cassette Holder from
the Retainer.
:
A
7.
If
necessary,
remove
the
Retainer
SY
Es
Pe
2
a
nS
from the chassis by taking off the
2 screws.
3-4.
HEAD/PINCH
ROLLER
A
3-4A. HEAD
1.
Remove
the
E-ring
(A)
and
remove
the
Spring
(C)
from
B
the
hook
(D)
of
the
Head
Base
Plate
and
the
tab
of
the
Pinch
Roller
Ass’y
(B).
2.
Remove
the
Pinch
Roller
Ass’y
from
the
pivot
stud
pin
(E).
[ N-M2
REC/PLAY HEAD
. 3-4B. PINCH ROLLER
After
removing
the
Trim
Case
Cover
(see
3-1),do
the
following procedure.
1.
Unsolder
each
lead
wire
from
the
terminal
pin
of
the
heads
to
facilitate
replacement.
To
re-solder
each
head
wire
to
the
newly
replaced
head,
refer
to
Fig.
3-5.
2.
Lift
up
the
heads
after
taking
off
the
hardware
mounting
them.
When
removing
the
nut,
do
not
loose
T-455
Washer
(F)
and
Spring
(G).
Fig.
3-4
Head/Pinch
Roller
Replacement
ERASE
REC/PLAY
NOTE
1.
After
replacing
the
head,
always
adjust
the
head
GRN
alignment
especially
the
Record/Playback
Head’s
BLU
azimuth
(see
7-1-1),
and
then
secure
the
screws
and/or
the
nut
with
a
drop
of
locking
paint.
T-463
Fig. 3-5 Head Wiring Diagram

2. Connect the wires to the head terminal pins
quickly to prevent breaking of internal wires of
the head due to overheating.
3. After replacement, always clean the driving
surfaces of the Pinch Roller with the TEAC
TZ-261B Rubber Cleaner or with pure alcohol,
then proceed directly to the PINCH ROLLER
PRESSURE adjustment section. See page 11.
3-5. BRAKE BRACKET
1. Remove the Trim Case Cover. See 3-1 section.
2. Remove the Cassette Holder. See 3-3 section.
3. Detach the 2 E-rings (A) and then take off the Spring
(B) and the Brake Bracket (C) from the chassis.
4. Remove each Brake Shoe (D) from the Brake Bracket.
3-6. CAPSTAN DRIVE ASS’Y/DRIVE BELT
1. Remove the Bottom Cover. See 3-1 section.
Detach the Flywheel Bearing Plate (A) from the
mounting studs (D and F) by taking off the 2 screws.
3. Take out the Drive Belt (C) from the Flywheel (B) and
the Motor Pulley (G).
4. Carefully lift out the Flywheel from the Capstan
Housing Ass’y (E).
5. Remove the Capstan Housing Ass’y from the chassis by
unscrewing the 3 screws.
NOTE
1. Since the Capstan Drive Ass’y is a precision part,
TEAC specially distributes the Flywheel and the
Capstan Housing Ass’y as a whole assembly.
Hence, always replace the Flywheel together
with the Capstan Housing Ass’y.
2. Clean all driving surfaces of the Flywheel and the
Drive Belt with TEAC TZ-261 Cleaner kit (“‘A”
for Flywheel. ““B” for Belt) or with pure alcohol.
3. Do not bend the Capstan Shaft as this will
increase wow/flutter or speed deviation.
4. During re-assembly re-attach the Drive Belt with-
out twisting or stretching it.
5. The Belt should always be attached right and in
the predetermined place.
Lubrication:
For lubrication of the newly replaced Capstan Drive
Ass’y, the following should be observed.
1. Apply a drop of a light machine oil of good
quality (e.g.: TEAC TZ-255) with an oil ap-
plicator to the shaft of the Flywheel and spread
oil evenly over the shaft with a flannel cloth.
Afier installing the Flywheel, be sure to clean the
tape moving portion of shaft with TEAC
TZ-261A Head Cleaner or with pure alcohol.
Viewed from
Bottom
Viewed from
Bottom
T-458
Fig. 3-7 Capastan Drive Ass’y/Drive Belt Replacements

Apply
a
drop
of
the
proper
oil
in
the
same
way
as
above
to
the
innermost
area
of
capstan
shaft
(next
to
the
Flywheel).
Apply
a
film
of
light
grease
to
the
well
of
the
Flywheel
Bearing
Plate.
3-7. REEL TABLE
1.
Remove the Trim Case Cover. See 3-1 section.
See
Fig.
3-8
for
step
2
to
4.
Remove
the
Spring
(A)
from
the
hook
(B)
of
the
Cassette
Holder
(D).
Loosen
the
screw
on
the
Stopper
Bracket
(C)
and
then
partially
turn
the
Bracket
in
the
direction
indicated
by
the
arrow.
Rotate
the
Cassette
Holder
away
from
the
Reel
Tables
(E
and
F).
Remove the Bottom Cover. See 3-1 section.
Remove
the
Drive
Belt
and
the
Flywheel.
See
3-6.
See
Fig.
3-9
for
step
7
to
9.
When
only
the
Supply
Reel
Table
(J)
is
to
be
removed,
first
take
out
the
Back
T464
Fig. 3-8 Rotation of Cassette Holder
Tension Bracket (H) riding in the Wheel by taking off
the Screw (G). At this time, note the predetermined
position (direction) of the Spring (I) for reinstalling.
For Detaching the Take-up Reel Table (K), first take
out the Large Counter Belt (L).
Take off the screws mounting the Reel Table which
requires replacement; next, with the PLAY key de-
pressed to release the Brake Shoes (M) from the Reel
Tables, pull out the table.
NOTE
Always
replace
the
complete
Reel
Table
Ass’y
as
an
entire assembly, ““Take-up” or “Supply”.
! Viewed from
Bottom
Ce we
Sy
bp
T-459
Fig. 3-9 Reel Tables Replacement

3-8. FAST WIND ROLLER ASS’Y
Pee
3-9. POWER TRANSFORMER
1.
2.
Remove the Trim Case Cover. See 3-1 section.
Rotate the Cassette Holder away from the Reel Tables.
See 3-7 section on page 9.
Remove the Bottom Cover. See 3-1 section.
Remove the Drive Belt and the Flywheel. See 3-6.
Remove the Spring (C) from the hook (G) of the F.F.
Lever.
Gently take off the 2 E-rings (B and H) and lift out the
Fast Wind Roller Ass’y (A) from the stud (F). In doing
this do not tilt the assembly at any angle as this may
damage the Roller Pin (D) and the Spring (E) or cause
them to be bent or broken.
If it is necessary to further disassemble the Fast
Wind Roller Ass’y, refer to the DETAIL OF “A”
figure.
NOTE
During remounting of the removed Fast Wind Roller
Ass’y, do the following:
1. Lubricate the entire shaft with a thin application
of light machine oil. (e.g.: TEAC TZ-255)
2. Clean the Fast Wind Belt and all friction surfaces
of the Rollers with TEAC TZ-261B Rubber
Cleaner or with pure alcohol before re-installing
the Belt.
2B, DETAIL
Cc M4xl0 OF ay ND
Remove the Trim Case Cover and the Bottom Cover.
See 3-1 section on page 6.
Unsolder each wire of the Power Transformer (B).
Note the color code and position of each wire prior to
unsoldering the Transformer leads.
Take off the 4 screws (G) and remove the complete
Transformer Ass’y (A) from the main chassis.
Separate the Transformer body and the Mounting
Plates (D, E, F) by taking off the 2 screws (C).
NOTE
When teinstalling the new Transformer, loosely
tighten the 2 screws (C) to attach the Transformer
body and the mounting plate (E). Then after attach-
ing the complete Transformer Ass’y (A) to the main —
chassis, position the transformer body by sliding it in & i a
either direction as shown by the arrows to find the : :
position that produces the lowest hum. After this,
firmly tighten the 2 screws (C). 4-BSA M3x8 T-a62
Fig. 3-11 Power Transformer Replacement
10

3-10.
PLAY
IDLER
ASS‘Y
1.
Remove
the
Bottom
Cover.
See
3-1
section.
2.
Take
out
the
Drive
Belt
and
the
Flywheel.
See
3-6.
3.
Lift
off
the
Play
Idler
Ass’y
(B)
with
the
Spring
(C)
removed
from
the
mounting
pin
(E)
and
the
E-ring
(A)
taken
off
from
the
pivot
stud
pin
(D).
4.
For
further
disassembly
of
the
Play
Idler
Ass’y,
refer
to
the
DETAIL
“B”.
When
remounting,
clean
the
driving
surface
of
the
Idler
with
the
TEAC
TZ-261B
Rubber
Cleaner
or
with
pure
alcohol.
Viewed
from
Bottom
T-46)
—————
.
Fig.
3-12
Play
Idler
Ass'y
Replacement
NOTE
All
the
mechanical
checks
and
adjustments
should
be
done
with
the
Trim
Case
Cover
removed.
(See
Section
3-1)
4-1,
PINCH
ROLLER
PRESSURE
Specification:
400
g
+
20
g
(13.5
~
15.0
02.)
1.
Switch
on
POWER.
2.
Place
the
deck
in
the
PLAY
mode
with
no
tape
loaded.
3.
Attach
the
spring
scale
to
the
Pinch
Roller
shaft
as
shown
in
Fig.
4-1.
4.
Gently
pull
the
scale
away
(in
the
direction
of
the
arrow)
until
the
Capstan
shaft
and
the
Pinch
Roller
are
completely
separated.
We
5.
Gradually
release
the
tension
on
the
scale
until
the
Piatt
Pinch
Roller
just
begins
to
rotate.
The
scale
should
Rae
2
ore
approximately
400
g
+
20
g
(13.5
~
Bend
here
to
adjust
Finis
6.
If
the
reading
is
out
of
specified
range,
adjust
the
Fig.
4-1
Pinch
Roller
Pressure
Measurement
tension of the Pressure Spring by bending the tab of
the Pinch Roller Ass’y slightly.
11

4-2. TAKE-UP TORQUE
Specification: 40 ~ 70 g-cm (0.6 ~ 1.0 oz-inch)
1.
2.
3.
mn
Rotate the cassette holder away from the reel tables.
See 3-7 section.
Switch on POWER.
Set the Cassette Reel Adapter (22 mm Dia.), connected
to the spring scale (0 ~ 70 g, or 0 ~ 2.5 oz.) by the
string as shown in Fig. 4-2 on the Take-up Reel Table.
Place the deck in the PLAY mode.
Allow the rotation of the Reel Table to pull the scale
pointer toward the Adapter with the spring scale
moving in the same direction at nearly the same speed
as the tape would be moved, and obtain the scale
reading. Make reading only when the pointer becomes
stable.
The scale should indicate Force of 36 ~ 64 g (1.3 ~
2.2 0z.).
This corresponds to a torque of 40 ~ 70 g-cm (0.6 ~
1.0 oz-inch). For the torque calculation, refer to Fig.
4-3.
If the reading is out of specified range, clean the
driving surfaces of the Reel Table Ass’y, and all other
driving parts relative to the take up torque function
with the TEAC TZ-261B Rubber Cleaner or with pure
alcohol
If the above cleaning is ineffective for torque correc-
tion, replace the Reel Table Ass’y. (See Section 3-7)
4-3. FAST FORWARD TORQUE
Specification: 100 g*cm (1.4 oz-inch) or more
1,
2:
12
Repeat step 1 and 2 in 4-2 above.
Set the Cassette Reel Adapter (22 mm Dia.), connected
to the spring scale (0 ~ 200 g, or 0 ~ 7.0 02.) by the
string as shown in Fig. 4-2, on the Take-up Reel Table.
Place the deck in the Fast Forward mode.
Allow the rotation of the Reel Table to pull the scale
pointer toward the Adapter, and obtain the scale
reading. Do not read until the pointer becomes stable.
The scale should indicate 91 g (3.2 oz.) or more.
This corresponds to a torque of 100 g-cm (1.4 0z-inch)
or more.
If the indication is out of specified range, clean the
driving surfaces of the Reel Table Ass’y and all other
driving parts relative to the fast forward torque
function with the TEAC TZ-261 B Rubber Cleaner or
with pure alcohol.
If the above cleaning is ineffective for the torque
correction, bend the spring (see Fig. 4-5) to get the
specified torque value.
Take-up Reel Table
Cassette Reel Adapter (22mm Dia.)
oo
Supply
Ree!
Table
T-406
Fig. 4-2 Take-up/Fast Forward Torque Measurement
Cassette Reel Adapter
T-409
T=Fxr For example:
T: torque (g*cm) If F=419
F: force (g)
r: radius (cm) T = Fxrer
= 41x1.1
= 45 (g*cm)
Consequently the torque is 45 g*cm.
Fig. 4-3 Torque Calculation Method
Cassette Reel Adapter (22mm Dia.)
; T-405
Fig. 44 Rewind Torque Measurement

Fig.
4-5
F.
FWD
&
Rewind
Torque
Measurement
4-4, REWIND TORQUE
Specification:
100
g
cm
(1.4
oz-inch)
or
more
1.
2.
Repeat
the
4-3
procedure,
but
use
the
Supply
Reel
Table
and
Rewind
mode
for
measuring
the
rewind
torque.
(See
Fig.
4-4)
The
specified
value
is
the
same
as
that
of
the
fast
forward
torque.
See
step
5
in
4-3.
4-5. BRAKE TENSION
1.
2.
3.
4.
Switch on POWER.
Load a TEAC MTT-S01 test tape.
Check
for
excess
slack
or
tightness
of
the
tape
when
operation
is
changed
from
play,
fast
forward
and
rewind
mode
to
stop
mode,
respectively.
If
brake
action
is
too
“tight”
or
“loose”,
adjust
by
bending
the
arms
of
the
Brake
Bracket
in
or
out
as
shown
by
the
arrows
in
Fig.
4-7.
TORQUE MEASUREMENT USING
THE CASSETTE TORQUE METER
The
torque
measurements
can
be
easily
done
with
the
Cassette
Torque
Meter
indicated
below.
For
take-up
torque
measurement:
0O~
100
g-cm
For
fast
forward
and
rewind
torque
measurements:
0
~
160
g-cm
By
use
of
this,
it
is
possible
to
directly
obtain
the
torque
value
without
calculation,
and
to
do
the
measurement
sim-
ply
with
no
removal
of
any
parts.
If
repairs
are
necessary,
the
Trim
Case
Cover
and
the
Bottom
Cover
must
be
removed.
Load
the
Meter
on
the
deck
and
read
the
pointer
indication
on
the
dial
scale
for
each
tape
movement
operation.
Fig. 4-7 Brake Tension Adjustment
13

4-6. TAPE SPEED/WOW AND FLUTTER
Specification:
Tape Speed Deviation: 3,000 Hz + 30 Hz
Wow and Flutter: Playback: 0.07% (WRMS)
Record/Playback:
0.10% (WRMS)
NOTE
Before performing this adjustment, clean all parts
in the tape path, particularly the Capstan, the
Pinch. Roller and the Heads with the appropriate
liquid from the TEAC TZ-261 Cleaner Kit or
with pure alcohol.
Wow and flutter should be checked in two ways;
Playback only and Record/Playback methods.
First check, and correct if necessary, tape speed
and wow and flutter using the playback only
method. Then measure wow and flutter using
record and playback method.
As the measured results may vary with respect to
location on tape at which it was taken, three
points — at beginning, middle and near the end
of the tape — should be measured.
4- i 1. TAPE SPEED
_
Connect test equipment to the deck, except the AF
oscillator, as shown in Fig. 4-8.
Set the OUTPUT control on the deck to proper setting.
Set the EQ switch to the “3” position, and then load
and play a TEAC MTT-111 test tape (3,000 Hz signal is
recorded).
Verify the reading on the frequency counter is within
the specified range of 3,000 Hz + 30 Hz.
If the tape speed is extremely out of the specification,
check the Pinch Roller pressure and the tape driving
function for correction, and make sure the tape path is
clean.
4-6-2. WOW AND FLUTTER
After making the tape speed measurement, perform the
wow and flutter test using the Playback Method and the
Record/Playback Method successively.
proeeee METHOD
3.
4.
14
Repeat steps 1 — 3 in 4-6-1.
Read the indication on the wow and flutter meter.
The wow and flutter value should be 0.07% WRMS,
max.
If the wow and flutter is out of the specification, check
the Pinch Roller pressure and the take-up torque, and
see that the tape path is clean, and that the Capstan
Beltis not stretched or oily.
If the above checks are ineffective for excessive wow
and flutter correction, repair or replace the Pinch
Roller, the Capstan Belt and/or any other detective
parts.
OSCILLATOR
FREQUENCY COUNTER
DECK wow & FLUTTER METER
LINE IN
(L}
under TEST
T4833
Fig. 4-8 Tape Speed/Wow and Flutter Measurement Setup
RECORD/PLAYBACK METHOD
NOTE
When using this method, adopt the maximum wow
and flutter value obtained by repeated play and stop
modes of operation. This operation is necessary to
make sure wow and flutter content between record
and playback will not be in phase to create a false
reading.
Connect test equipment to the deck as shown in Fig.
4-8.
Set both LINE and OUTPUT controls on the deck to
proper setting.
Load a TEAC MTT-502 test tape (blank) and set the
BIAS/EQ switches in the “3” positions.
Apply and record a 3,000 Hz signal.
Rewind and play this recorded portion.
Read the indication on the wow and flutter meter.
The wow and flutter value should be 0.10% WRMS, max.
If the measured value is out of the specification, repair
using the same methods as stated in steps 4 — 5 inthe
Playback Method procedure.
BOTTOM VIEW w/
FLYWHEEL REMOVED
FAST WIND
ROLLER reel we IDLER
SUPPLY TAKE-UP
REEL TABLE REEL TABLE
T-481
Fig. 5-1 Bottom View w/Flywheel Removed

5.
PARTS
LOCATION
TOP VIEW
SUPPLY
REEL
TABLE
TAKE-UP
REEL
TABLE
DOLBY
FM/COPY
CAL
PC
BD.
CASSETTE
HOLDER
REC/PB
AMPL.
PC
BD.
MUTING
SWITCH
DOLBY
B-TYPE
PRCESSOR
PC
BD.
[P
BD.
a
ERASE
HEAD
CAPSTAN
DRIVE
ASSY
REC/PLAY
HEAD
PINCH
ROLLER
1-479
Fig.
5-2
Top
View
BOTTOM
VIEW
DRIVE
BELT
MOTOR
PULLEY
ne
SOLENOID
POWER TRANSFORMER
POWER
SUPPLY
PC
BD.
yoane
Fig. 5-3 Bottom View
q
1
E

6. LUBRICATION
NOTE
Lubrication should be generally done at about
every 1,000 hours of operating time of the tape
deck. Use high quality oil for this purpose.
For efficient oiling, it is recommended that re}
lubrication be done after nearly 1 hour of idling 8
of the deck.
No other lubrication is normally necessary with
the following exceptions.
6-1. MOTOR
Apply 1 or 2 drops (approx. 0.2 cc) of a light machine oil | °
with an oil applicator to the oiling hole of the Motor. ,
6-2. CAPSTAN ASS'Y
Apply 1 or 2 drops (approx. 0.2 cc) of a light machine oil
with an oil applicator to the shaft bearing portion of the
Capstan Assy.
6-3. FLYWHEEL ASS’Y
See Section 3-6 for lubrication of the newly replaced | —~Capstan Assy
Fig. 6-2 Lubrication of Capstan Ass’y
Flywheel Assy.
16
7. ELECTRICAL CHECKS AND ADJUSTMENTS
**
GENERAL NOTICE
Before performing adjustments on the amplifier section of
this deck, thoroughly clean and demagnetize the entire tape
path, particularly erase head, record/playback head, capstan
shaft and pinch roller.
Make sure the deck is set for the proper voltage and
frequency for your locality.
In general, checks and adjustments for other than specified
items, are done in the sequence of left channel then right
channel. Double designated REF. NO. indicates left channel/
right channel (example: VR101/201).
Value of “dB” in the text refers to 0 dB = 0.775 V, except
where specified. If a VTVM calibrated to 0 dB= 1 Vis to be
used, appropriate compensation should be made.
The VTVM used in the procedures, including the measure-
ment at CAL test points, must have load impedance of 1 MQ
or more.
To correctly complete these performance checks, keep the
order as explained in this chapter.
All checks and adjustments should be made with all Cabinet
parts, except for the Front Panel, removed. (See Section 3-1)
For each procedure, make the initial equipment test set up,
connections and switch/control settings as shown in the
associated illustrations.
Each of the switches shown in the boxed-in area of the
photograph have effect on the procedures.
a)
Fig. 6-1 Lubrication of Motor
Apply lor2 drops
jt (approx. O.2cc) of Oil here
T~408

7-1. PLAYBACK PERFORMANCE
NOTE
Except
for
the
Playback
Frequency
Response
checks,
all
alignments
in
the
PLAYBACK
PERFORMANCE
only
have
to
be
done
with
the
EQ
switch
set
to
position
3
unless
there
is
a
special
reason
which
requires
that
other
positions
also
be
checked.
7-1-1. RECORD/PLAYBACK HEAD AZIMUTH
1.
Gp
ADJUSTMENTS
Load and play a TEAC MTT-150 test tape.
Make sure the phase relationship between the 2 signals
(left
channel
and
right
channel)
is
within
45°
on
the
oscilloscope.
Load a TEAC MTT-116U test tape.
Play the 10 kHz signal section of the tape.
Slowly
adjust
the
azimuth
adjusting
nut
for
the
maximum indication on the VTVM.
Secure the nut with a drop of locking paint.
0° 45° 90° 180°
’
'
c
{
’
IN PHASE OUT OF PHASE
Fig. 7-1 Confirming Phase Relationship
Adjusting Nut
R/P Head
Fig.
7-2
Head
Azimuth
Adjustments
Location
7-1-2. SPECIFIED OUTPUT LEVEL SETTING
1.
2.
3.
4.
5
Load and play a TEAC MTT-150 test tape.
Adjust VR102/202 for 100 mV (—18 dB) on VTVM
connected to the CAL test points.
Change the VITVM connection to the OUTPUT jacks.
Set the OUTPUT controls fully clockwise.
Confirm that the output level is —3.5 dB + 1 dB (461
mV ~ 580 mV).
Set
the
OUTPUT
controls
for
a
reading
of
—5
dB
(435
mV).
This
is
the
specified
output
level.
At
this
time,
the
physical
position
of
the
OUTPUT
controls
indi-
cates
the
Specified
Control
Settings
referred
to
in
subsequent
procedures.
IMPORTANT
After this setting is done, do not disturb the Specified
Control Setting of the OUTPUT controls until the remain-
ing checks and adjustments are completed.
CONNECTION
OSCILLOSCOPE
under TEST
T- 389-2
Fig. 7-3 Connection
SWITCH & CONTROL SETTING:
T-469
OUTPUT Control: Proper setting
CONNECTION
(A)
E Wei Pe ine Edis Piao tid
DOLBY B-TYPE PROCESSOR PC BD.
DECK under TEST
U
OSCILLOSCOPE
(B)
Fig. 7-4 Connections
SWITCH & CONTROL SETTING: Same as 7-1-1.
srenonmemaihtt tame
17

7-1-3. VU METER CALIBRATION —PLAYBACK—
7.
8.
Adjust VR107/207 for +3 VU (D0) on the VU meter.
Set the DOLBY NR switch to the IN position and
make sure the VU meter indication is the same, also.
7-1-4. FREQUENCY RESPONSE —PLAYBACK—
NOTE
In the following procedure, adjust VR101/201 so
that the measured values on all setting of the EQ
switch are within the specified response limits.
Hi-Fi TAPE
9.
Load a TEAC MTT-116U test tape and play its test
signals from 40 Hz up to 14 kHz.
10. Adjust VR101/201 so that the readings of the higher
frequency signals on the VTVM are within the response
limits.
CrO, & Fe-Cr TAPES
11. Repeat the above procedure, with the following ex-
ceptions.
Test tape: MTT-116K
EQ switch: Both “1 & 2” positions
RESPONSE IN dB
ea + +
bon FO NM fb
ai ee , TTT Pee EES PL oa
: |.TEST TAPE: MTT-116U (EQ 3)
TTT | MTT-116K (EQ 1, 2)
+t 4+ o oe
+2 +2 Li |
$titt |
=E a
ca
+ Ht tt +
FREQUENCY IN Hz
Fig. 7-5 siceeci pee heirs Limits
NOTE
If the response does not meet the specified response
limits, the head should be checked for accumulated
oxide or dirt. Then, if no dirt is found, the head
azimuth should be readjusted.
7-1-5. SIGNAL TO NOISE RATIO —PLAYBACK—
—
Place the deck in the PLAY-PAUSE mode.
Read the indication on the VTVM.
The VTVM should indicate -52 dB minimum (1.94
mV maximum).
This corresponds to a signal-to-noise ratio of 47 dB
(minimum): difference between residual noise —52 dB
and the specified output level —5 dB (435 mV).
NOTE
Since the polarity of the AC plug has some effect on
the signal-to noise ratio, the plug can be reversed in
the wall socket when checking the signal-to-noise
ratio. The’ worse case value should be within the
indicated value above.
Specification: 47 dB (minimum)
18
Porn mt tn! rier w noun ete npRer ernie er tote eu EARTH,
CONNECTION: See Fig. 7-4 (B) :
SWITCH & CONTROL SETTING: '
4 Hy
'
2 j
i
3 NORMAL '
T-470
OUTPUT Control:
Specified Control Setting (See 7-1-2)
OLBY arz|
FM/ COPY ~ SOURCE

7-1-6.
HEADPHONE
OUTPUT
LEVEL
CHECKS
NOTE
An 8 ohm non-inductive resistor should be used as
the test load resistor.
1. Load and play a TEAC MTT-150 test tape.
2. Measure the level across the test load resistor.
Specification:
—21
dB +2 dB
(54.8
mV
—
86
mV)
CONNECTION
VTVM
DECK under TEST
T-401-1
Fig. 7-6 Connection
SWITCH & CONTROL SETTING:
1-469
OUTPUT Control: Specified Control Setting (See 7-1-2).
7-2. MONITOR PERFORMANCE
7-2-1.
MINIMUM
INPUT
LEVEL
CHECKS
NOTE
To prevent mis-measurements for the following pro-
cedures, any connection cords other than these for
the respective input check must be removed.
For example: Do not connect the Microphone and
the DIN cords to respective input jacks when check-
ing for the LINE inputs.
Load any recordable tape.
Place the deck in the RECORD-PAUSE mode.
Set the MIC controls to maximum.
Apply a 400 Hz signal at -67 dB + 2 dB (274 uV ~
435 pV) to the MIC jacks and check for 100 mV (18
dB) on the VTVM connected to the Dolby test points.
(Minimum Input Level checks for the MIC jack)
5. Apply a 400 Hz signal at -35 dB + 2 dB (10.9 mV ~
17.3 mV) to the input terminals of the DIN connector
and check for 100 mV. (Minimum Input Level checks
for the DIN inputs)
6. After checking, reduce the MIC controls to minimum
to prevent noise insertion during subsequent pro-
cedures.
7. Set the LINE controls to maximum.
8.
Apply
a
400
Hz
signal
at
—15
dB+2
dB
(109
mV
~
173 mV) to the LINE IN jacks and check for 100 mV.
(Minimum Input Level checks for the LINE inputs)
PWN
z
CONNECTION
VTVM
OSCILLATOR
DECK under TEST 1-477
Fig. 7-7 Connection
SWITCH & CONTROL SETTING:
1-471
OUTPUT
Control:
Specified
Control
Setting
(See
7-1-2)
LINE
Control:
Minimum
Setting
MIC
Control:
Minimum
Setting
i ao an te SIREN RON Bete agate
19

7-2-2. SPECIFIED LINE CONTROL SETTING
9. Apply a 400 Hz signal at —-5 dB (435 mV) to the LINE
IN jacks. See Fig. 7-8.
10. Set the LINE controls to obtain the reading of 100 mV
(-18 dB) on the VTVM. At this time, the physical
position of the LINE controls indicates the Specified
LINE Control Setting referred to in subsequent pro-
cedures.
IMPORTANT
After this setting is done, do not disturb the Specified
Control Setting of the LINE controls until the
remaining checks and adjustments are completed.
7-2-3. DOLBY FM/COPY CAL CONTROL
SETTING
11. Set the DOLBY FM/COPY switch to IN and apply a
400 Hz signal at -14 dB (154 mV) to the LINE IN
jacks.
12. Set the DOLBY FM/COPY-CAL controls on the A-450
rear panel to obtain the reading of 100 mV (—18 dB)
on the VTVM.
NOTE
When the DOLBY FM/COPY switch is IN, the LINE
and MIC controls have no control over the input
signal and only the DOLBY FM/COPY CAL controls
(on the back panel) can adjust the input level.
However, for the convenience of the following
procedure, do not disturb the LINE and MIC control
settings.
7-2-4, VUMETER CALIBRATION —RECORD-
13. Set the DOLBY FM/COPY switch to OUT and apply a
400 Hz signal at —5 dB (435 mV)
14, Adjust VR106/206 for +3 VU (D0) on the VU meter.
7-2-5. LED PEAK LEVEL INDICATOR
CALIBRATION
15. Adjust VR108 so that the PEAK LEVEL indicator
lights as shown in Fig. 7-9, when a 400 Hz signal is
applied at required level to the left channel LINE IN
jack. Keep the right channel LINE IN jack discon-
nected from an AF oscillator.
16. For the right channel, repeat the above procedure
except adjust VR208. Keep the left channel LINE IN
jack disconnected from the AF oscillator.
17. After setting both channels, make sure when required
signal is simultaneously applied to both channels, the
indicator reacts the same as above.
20
VTVM
OSCILLATOR
LINE IN
DOLBY B-TYPE PROCESSOR PC BD.
DECK under TEST oe
Fig. 7-8 Connection
OSCILLATOR
PEAK LEVEL
400Hr (Indicator
ATTENUATOR
DECK under TEST
t
ut
v lights at
(615mv) -2 TT SEES tall intensity
(488mv) -4 ~---(@) goes ot completely
Specified
igut Lever C= —5 |
Fa
= ‘
a
s
4
rs :
>
z
PEAK LEVEL
indicator Ta0o=
Fig. 7-9 LED Peak Level Indicator Setting