Teac A-4000 User manual

TEAC
A-4000
STEREO
TAPE
PLAYER
A-4010
STEREO
TAPE
RECORDER
SERVICE
MANUAL
TEAC
CORPORATION
CA

pS a oe Mla a
The
serial
number
of
TEAC
Model
A-4000-Series
starting
at
#8354
is
hereby
announced
that
the
head
alignment
has
been
altered
as
the
following
Fig.
9-1
instead
of
previous Fig. 9.
REVERSE FORWARD
PLAYBACK
HEAD
PLAYBACK
HEAD
AZIMUTH
HEIGHT
AZIMUTH
HEIGHT
ERASE
HEAD
RECORD
HEAD
AZIMUTH HEIGHT
PLAYBACK RECORD PLAYBACK
ERASE HEAD peyERSE HEAD HEAD FORWARD HEAD
FIG, 9-1 HEAD ALIGNMENTS

TABLE OF CONTENTS
SPECIFICATIONS
COMPONENT LOCATION ....
DISASOEMBLY 20% sh gals w? Selma
CONTROL BUTTONS .....
MECHANISM ADJUSTMENTS ,
° °
ALIGNMENT AND PERFORMANCE CHECKS .
MAINTENANCE . 2... wu
TROUBLE SHOOTING .....
e
e e
TRANSPORT MECHANISM WIRING DIAGRAM
AMPLIFIER SCHEMATIC DIAGRAM
RECORDING AMPLIFIER SCHEMATIC DIAGRAM
EXPLODED VIEW AND PART NO. .
« °
Page
12
14
20
33
35
38
39
40
41

SPECIFICATIONS
Heads Four, 4 track 2 channel Erase, Record,
Forward playback and Reverse playback
Reel Size 7" maximum
Tape Speed 7 ¥2 and 33/4 ips (40.5%)
Motors 1-Dual speed hysteresis motor for capstan
drive
2-Torque motors for reel turntables
Wow and Flutter 71/2 ips 0.12%
33/,
ips
0.15%
Fast Winding Time Approximately 70 seconds for 1,200 feet
Frequency Response 7/2 ips 30 to 20,000 cps @
(43 db 50 to 15,000 cps)
33/4 ips 40 to 12,000 cps
(43 db 50 to 7,500 cps)
Equalization 50 microseconds (NAB) for 71/2 ips
120 microseconds(EIA) for 33/4 ips
Signal to Noise Ratio 50 db at 71/2 ips (peak record level to
unweighed
Crosstalk 50 db channel to channel at 1,000 cps
40 db between adjacent tracks at 100 cps
Input (RA-40) Microphone: 10,000 ohms, 0.25mV minimum
Line: 100,000 ohms, 0.14V minimum
Output 12 volts for a load impedance 100,000 ohms or
more
Power Requirements 100/117/200 VAC, 50 or 60 cps
A-4000, A-4OLOL: 100 VA
A-4010 : 110 VA
Dimensions A-4000 : 17Y4" x 13" x 9 Yate
A-40L0L: 17 Yyu x 17 You x 9 Yan
RA-4O : 17 YA" x 59/16" x 9 Yan
A-4010 : 174/4r x 17Yan x gl/an
We ight A-4000 : 37 Lbs
A-4O0LOL: 40 Lbs
RA-4O :; 10 Lbs
A-4010 : 48 Lbs
Due

COMPONENT LOCATION
A-4000 PLAYER (DECK) AD
FIG. 1 A-4000 DECK

OO OOO
©
GOGO © © ©®©
©
Reel Holder
Left Reel Turntable Shaft
Left Reel Turntable
Tension Arm
Sensing Post - permits automatic switch-over to
reverse playback upon contact with
the sensing foil on the tape.
Control Buttons - select tape operation.
Press for forward playback.
Press for reverse playback.
Press and [FAST
for fast forward,
Press and for rewind.
Head Assembly
Tape
Lifter
-
lifts
tape
from
heads
during
fast
wind operation,
Capstan - drives tape in recording and play-
back mode.
Pressure Roller
(Pinch
Roller)
-
drives
tape
with
capstan.
Power
Pilot
Lamp
-
turns
on
when
equipment
is
energized.
Power
Switch
-
turns
recorder
on or
off.
Tape
Speed
Selector
Switch
-
selects
tape
speed
and
appropriate
equalizer circuit.
position: 71/2 ips (19 cm/s)
position: 33/4 ips (9.5em/s)
Automatic Shut-off Lever ~ shuts off power to transport when
tape runs out.
Right Reel Turntable Shaft

G @O©@
® ©
® ®
®@OOQ®
Right Reel Turntable
Index
Counter
-
indicates
tape
position,
resets
when
button is pressed.
TAPE TENSION |
Tape
Tension
Selector
Switch
-
provides
weaker
tape
tension
when
a
1/2
mil
or
thinner
tape
is
used.
Playback
Preamplifier
Output
Jacks
(OUTPUT)
EQUALIZER
TO
AMP!
Socket
-
for
connection
to
the
equalizer
of
the record amplifier.
Remote Control Socket
[TO
REC.
AMP.!
Socket
-
for
connection
to
the
racerd
amplifier,
Fuse
-
Replace
only
with
2
ampere
fuse,
AC POWER IN} AC Power Cord Receptacle
[c/s SELECT! AC Power Supply Frequency Selector Switch
VOLTAGE SELECT; AC Power Supply Voltage Selector Switch

RA-40 RECORD AMPLIFIER
@ ® ©
@ ®
2 ©®@ 8
FIG. 2
MIC IN| Mic Input Jacks
ip
Mic Level Control
Line Level Control
NOTE: Level controls shown 62) 63) and 69) above are dual
potentiometers.
Inner
knob
(Channel
A)
is
friction
coupled with outer knob (Channel B) to be operated
together or separately.
Level Indicator Meter for Channel A
Level Indicator Meter for Channel B

CRGRORCEC)
©)
@@POe®
Record Pilot Lamp for Channel A
Record Pilot Lamp for Channel B
RECORD SELECT! Record Selector Buttons
PLAYBACK] Playback Level Control
MONITOR] Monitor Selector Switch
SOURCE: position:
[TAPE] position:
Head Phone Jack
TO DECK OUTPUT
Playback Input Jack
TO DECK EQUALIZER
Record Equalizer Socket
[REC/PLA¥| Record Input and
Playback Output Jack
LINE! Line Input Jack
OUTPUT] Output Jack
TO DECK; Socket
FUSE 2 AMP.; Fuse
The input signal to be recorded
can be reproduced through head-
phones or speaker system while
the VU meter indicates the level.
During playback or while record-
ing, recorded signal on the tape
can be reproduced as above.
for connection to the preampli-
fier output of the A-4000 deck.
for connection to tape speed
selector switch,
for DIN (Deutsche Normen)
connection.
Replace only with 2 ampere fuse.

DISASSEMBLY
REMOUNTING UNIT FROM CASE (Refer to Figs. 3 ~ 5.)
1. Remove power cord, remote or shorting plug and audio cables,
2. Remove two screws (3)
3. Lay the recorder face down on a soft mat.
4. Remove the back panel <6) from the rear of the case by removing
eight
screws
(5)
and
disconnect
the
TO
REC
AMP
cable
and
equal-
izer cable.
5. Remove the case Q@) from the transport by removing four screws Qo.
6. Turn the recorder and lay the recorder face up on a soft mat.
7. Remove the following parts and hardware (see Fig. 3).
Pinch roller 3)
Dust cap (2)
Reel tables (7) (left and right) by removing three (each)
screws (6)
Head housing (5) by removing screw (4)
Four mounting screws (8
Face plate (9)
REMOVING AMPLIFIER FROM CASE (Refer to Fig. 4)
1. Remove the cable of TO TRANSPORT and EQUALIZER connectors.
2. Remove four screws 6) (4).

RA-—40
RECORD
AMPLIFIER

my”
a°
=
St
on
Oe
Hibs
“Ma
Ao
ey
Pr
id
=,
-
\
eT
a
A
y
Cl
e
e
7
a,
=
anr i tee
Sitti,
|F
jisei=
==
Pie
SS
<a
SO SH
at
S =e 7 |
O ASS)
Gy
i
-C
=
A—4000 TAPE PLAYER

SUFTT
¢
AY
Seco,
A/a
Baer
A
_
‘ES
\

CONTROL BUTTONS
Tape
transport
selector switches
consist
of
4
push-buttons,
7
nicro-
switches
and
a
solenoid
for the
fast
button
(Fig.
21).
The
push-button
operate
the
transport
for
the
following
functions:
(See
Figs.
15
thru
17)
®
1.
FORWARD
PLAY
(button
marked
[>
)
When
the
forward
play
button
is
depressed:
a.
The
brake
solenoid
is
energized,
freeing
the
turntables,
This
solenoid
latches
itself
and
remains
energized
after
the
button
is
released.
b.
Reduced
voltages
are
supplied
to
the
left
and
right
reel
motors
through
resistors
R304
and
R303
respectively.
ce.
The
pinch
roller
solenoid
is
energized,
pulling
the
pinch
roller
against the capstan.
2.
REVERSE
PLAY
(marked
<<
)
When
the
reverse
play
button
is
depressed:
a.
The
brake
solenoid
is
energized,
freeing
the
turntables.
b.
Relays
RL-2,
RL-3
and
KL-4
are
energized.
c.
RL-3
reverses
drive
motor
rotation
by
switching
the
polarity
of
one
main
field
winding.
d.
RL-2
reverses
reduced
voltage
supply
to
left
and
right
reel
motors
by
selecting
preset
taps
on
K-304
and
R-303
respectively.
3. STOP
Depressing
the
STOP
push-button
releases
all
relays
and
solenoids,
Voltage
is
removed
from
the
capstan
and
reel
motors.
Brakes
are
en~-
gaged through spring tension.
4.
FAST
FORWARD
When
the
FORWARD
and
FAST
buttons
are
depressed
either
simultaneously
or
FORWARD
and
FAST
in
that
order:
a.
The
brake
solenoid
is
energized,
freeing
the
reel
turntables.
Full
AC
line
voltage
(117
volts)
is
supplied
to
the
right
reel
motor.
ce.
The
pinch
roller
solenoid
is
not
energized.
ae oe

5.
REWIND
When
the
REVERSE
and
FAST
buttons
are
depressed
either
simultaneously
or
REVERSE
and
FAST
in
that
order
similar
functions
are
performed
as
described
in
FAST
FORWARD
operation.
However,
relay
RL-2
is
ener-
gized,
reversing
supply
voltages
to
the
reel
motors.
RECORD (RA-40 Record Amplifier only)
When
the
REC
buttons
of
CHAN-A
and/or
CHAN-B
are
depressed,
record
relays
RL-5
and/or
RL-6
are
energized,
These
relays
apply
voltages
to
the
following
points:
a. B- to the bias oscillator
b. Bias and audio signals to the record heads
c. Erase current to the erase heads
AUTOMATIC REVERSE PLAY
Permits
automatic
reversing
of
tape
travel
by
placing
sensing
foil
at
end
of
tape.
When
the
sensing
pole
is shorted
by
sensing
foil,
sensing
relay
RL-l
is
energized
and
all
functions
as
described
in
REVERSE
PLAY
occur.

MECHANISM ADJUSTMENTS
PINCH ROLLER PRESSURE ADJUSTMENT
The
pinch
roller
is
forced
against
the
capstan
by
the
action
of
pinch
roller
solenoid
(58,
Fig.
6).
Pinch
roller
pressure
is
supplied
by
the
pinch
roller
pressure
spring,
and
is
adjusted
by
a
lock
nut
on
the
capstan
solenoid
spade
bolt
(31,
Fig.
6).
The
recommended
pro-
cedure
for
adjusting
pinch
roller
pressure
is
as
follows.
1.
Hold
the
shut-off
lever
so
that
the
shut-off
lever
switch
is
held
in
the
operate
position
(A
rubber
band is
convenient
for
this
purpose)
.
2. With the POWER switch in the ON position, press the PLAY button,
and note whether the capstan solenoid plunger is bottomed. The
pressure against the capstan shaft should be approximately 4.4
pounds,
3. If it is desired to measure pinch roller pressure, press the STOP
button, and using a string about 20 inches long, tied in a loop
Slip the loop between the pinch roller and roller arm so that the
string rests against the pinch roller shaft.
4. Attach the other side of the loop to a 0 to 8 pounds scale, let-
ting the string remain slack.
5. Press the PLAY push-button, causing the pinch roller to clamp
against the capstan.
6. Pull the scale away so that the string is taut and makes a 90
degree angle with the pinch roller arm.
7. Slowly pull the scale away with sufficient strength to cause the
pinch roller to pull away from the capstan, reading the scale at
the instant the pinch roller leaves the capstan. The scale read-
ing should be 4~ 5 pounds, If necessary, adjust the nut (28,
Fig. 6).
NOTE: Reduced pinch roller pressure can result from either two
extremes of adjustment. Remember that maximum efficiency
is obtained from the solenoid only when its plunger is
"exactly bottomed",
es ae

- 6T -
-- CAPSTAN
i et i; ; - - PINCHROLLER
| 2 ‘
:
.
a@ @ S
FIG. 6
|
PINCHROLLER PRESSURE ADJUSTMENT

TO RIGHT MOTOR
ELU
SO R-303
|| A. REV BACK TENSION
aco B, FORWARD TAKEUP TENSION
PNK
feo a en = Nas
=f | f R-305...FOR 1/2 MIL TAPE
| A. FORWARD BACK TENSION
| J B. REV BACK TENSION
TO_LEFT MOTOR
R-304
A. REV TAKBUP TENSION
B. FORWARD BACK TENSION
RED
W/RED/GRN
NOTE: - «A or B > DECREASE TENSION DIRECTION
* REV: REVERSE
FORWARD BACK actor : REVERSE BACK TENSION
SPRING SCALE MOTION
REVERSE TAKEUP See ay § FORWARD TAKEUP TENSION
TENSION SW.
wy
FIG. 7 TAKEUP AND SUPPLY TENSION ADJUSTMENTS
- 16-

TAKE-UP AND SUPPLY TENSION ADJUSTMENTS
Take-up and supply tensions in forward and reverse play mode are de-
termined
by
the
positioning
of
the
sliders
on
resistors
R-303,
R-304
and R-305, located on the tape transport control chassis (Fig. 7).
The
torque
of
both
the
left
and
right
reel
motors
must
be
adjusted
as
follows: -
left motor right motor
forward play 3.5 + 0.7 in-oz 4.1 + 0.7 in-oz
reverse play 4.1 + 0.7 in-oz 3.5 + 0.7 in-oz
1.
Place
an
empty
7
inch
reel
having
4
inch
diameter
hub
on
the
tape
supply turntable.
2.
Turn
on
the
power
switch
and
set
the
tape
tension
selector
switch
to normal.
3.
Block
the
shut-off
lever
switch
in
the
operate
position,
4.
Make
small
loops
at
both
ends
of
a
30
inch
piece
of
string.
5,
Attach
one
loop
to
the
tape
anchor
on
the
reel
hub
and
the
other
to a 0 to 4 oz. spring scale.
6,
Operate
the
PLAY
button
and
allow
the
clockwise
motion
of
the
left
reel to draw a turn of string onto the hub.
7,
Make
certain
that
the
string
is
now
parallel
to
the
plane
of
the
top
of
the
tape
transport
and
that
the
string
is
centered
and
not
touching either reel flange.
8.
Let
the
reel
motor
pull
the
string
slowly
onto
the
hub
by
follow-
ing
the
torque
motor
force
with
the
scale
while
observing
the
readings
on
the
scale
until
a
constant
reading
is
obtained.
9,
If
necessary,
adjust
the
slide
B
on
resistor
R-304
on
the
control
chassis
until
a
scale
reading
between
1.4
and
2.1
ounces
is
achieved.
10.
Next
operate
the
reverse
play
(<<
),
and
check
the
torque
using
the
same
procedure
as
above.
However,
spring
scale
motions
are
reversed
(see
Fig.
7),
the
scale
should
indicate
approximately
1.7~
2.4
ounces
by
adjusting
the
slide
A
on
resistor
R-304.
- 17 -

11. Use the procedures in the preceding steps to check and adjust the
right reel motor tensions which are set by the slide A on R-205
(approx. 1.7~ 2.4 oz.) for forward play, and slide B on R-=205
(approx. 1.4~ 2.1 oz.) for reverse play.
12, Set the tape tension selector switch to the 1/2 mil position.
Then check the torque using the same procedure as above. The
scale should indicate a decrease of approximately 0.3 ounce less
than the normal tension readings.
BRAKE ADJUSTMENT
Brake adjustment is made with no power applied to the equipment
(Fig. 8).
iL.
2.
3.
Place an empty 7 inch reel having 4 inch diameter hub on the left
reel turntable.
Make small loops at both ends of a 30 inch string.
Attach one loop to the tape anchor on the reel hub and the other
to a 0O~10 oz. spring scale.
Wind several turns of string onto the hub, counterclockwise,
Pull
the
scale,
making
certain
that
the
string
does
not
touch
either
flange
of
the
reel.
The
turntable
will
rotate
counterclLock-
wise.
Take
a
reading
only
when
the
turntable
is
in
steady
motion,
as
the
force
required
to
overcome
the
static
friction
will
produce
a false and excessively high initial reading.
Adjust
the
left
motor
brake
by
positioning
the
brake
adjusting
spring
arm
(54,
Fig.
8) for
a
scale
reading
of
approximately
5.5~
7
ounces
(11~
14
in-oz.).
To
adjust
the
brake
on
the
right
reel
turntable,
repeat
the
ertire
procedure
as
described
for
the
left
reel
turntable,
with
the
«xcep-
tion that all directions of rotation are reversed.
NOTE: The difference in reading of the right and left reel
turntable
brakes
should
be
kept
within
2.8
inch-ounces,
- 18 -