Teac V-2RX User manual

TEAC.
SERVICE MANUAL
V-2RX/V-4RX
Stereo Cassette Deck
Effective: November, 1982 B-20187 5704016100

-V-2RX/V-4RX _
1
SPECIFICATIONS
AND
SERVICE
DATA
Notes:
1.
Improvements
may
result
in
changes
in
specifications
and
service
data.
2.
O
dB
is
referenced
to
0.775
V
in
this
manual.
SPECIFICATIONS
Track
system
4-track,
2-channel
stereo
Heads
3:
Erase,
record
and
playback
(V-2R
xX)
2:
Erase,
record/playback
(V-4RX)
Type
of
tape
Cassette
tape,
C-60
and
C-90
(Philips
type)
Tape
speed
4.76
cm/s
(1-7/8
ips)
Input
(level
and
impedance)
MICRO-
PHONE:
Specified
input
level:
~57
dB
(1.09
mV)/10
kahms
Minimum
input
level:
-67
dB
(346
nV)
LINE
IN:
Specified
input
level:
-9
dB
(275
mV)/50
kohms
Minimum
input
level:
~19
dB
(86.9
mV}
Output
(level
and
impedance)
OUTPUT:
Specified
output
level:
-3.5
dB
(518
mV)/
50
kohms
PHONES:
Specified
output
level:
-15
dB
(138
mV)/8
ohms
Equalization
‘METAL:
3180
us+
70us
Co(CrO,):
3180us+
70us
NORMAL:
3180
ys
+
120
us
Head configuration
1/2-track, 1-channel erase head
1/4-track,
2-channel
record
and
playback
head
(V-2RX)
1/4-track,
2-channel
record/playback
head
(V-4RX)
Motors
1
DC
servo
motor
(for
capstan
drive)
4 DC motor (for reel drive)
Bias frequency 100 kHz
Operation
position
Horizontal
Power requirements
100/120/220/240
V
AC,
50/60
Hz,
29
W
(V-4RX:
28
W)
(General export)
120
V
AC,
60
Hz,
29
W
(V-4RX:
28
W)
(U.S.A./Canada)
220
V
AC,
50
Hz,
29
W
(V-4RX:
28
W)
(Europe)
940
V
AC,
50
Hz,
29
W
(V-4RX:
28
W)
(U.K./Australia)
Weight
7.0
kg
(15-7/16
Ibs.)
net
Dimensions
277 mm (10~7/8")
280 mm (11"')
SERVICE DATA
MECHANICAL
Tape
speed
deviation
3,000
Hz
=
70
Hz
Tape speed drift 70 Hz
Wow and flutter
Playback: 0.06% (WRMS)
Record/playback: 0.25% (RMS)
Pinch
roller
pressure
350
g
to
450
g
(12.3
oz
to
15.9
oz)
Reel Torque
Take-up:
35
to
65
g-cm
(0.49
to
0.90
oz-inch)
Supply: 2 to 4 g-cm (0.028 to 0.056 oz-inch)
FF./
REW:
80
to
150
g-cm
(1.1
to
2.1
oz-inch)
Fast
winding
time
90 seconds for MTT-501 (C-60)
ELECTRICAL
Frequency response
See Figs. 5-6 and 5-8 to 5-10
Signal-to-noise ratio
Playback: NORMAL: 47 dB min.
Overall: METAL, Co (CrO,): 46 dB min.
NORMAL: 45 dB min.
Erase
efficiency
65
dB
min.
at
1
kHz
(measured
with
input
10
dB
higher than the specified input level)
Channel separation 30 dB min. at 1 kHz
Adjacent track crosstalk 40 dB min. at 125 Hz
Total
harmonic
distortion
1.8%
or
less
with
METAL
and
Co
(CrO.,) tapes
2.0% or less with NORMAL tape
e
Dolby
Noise
Reduction
System
manufactured
under
license
from
Dolby
Laboratories
Licensing
Corporation.
“Dolby”
and
the
double-D
symbol
are
trademarks
of
Dolby
Laboratories
Licensing
Corporation.
e
dbx
Noise
Reduction
system
made
under
license
from
dbx,
Incorporated.
The
name
“dbx”
and
the
dbx
symbol
are
trademarks
of
dbx,
Incorporated.
CAUTION
¢.
Parts
marked
with
this
sign
are
safety
critical
components.
They
must
always
be
replaced
with
identical
components
—
refer
to
the
appropriate
parts
list
and
ensure
exact
replace-
ment.

V-2RX/V~4RX
2
CASE
AND
FRONT
PANEL
REMOVAL
umbe
Disassemble in n
Fig. 2-1

V-2RX/V-4RX
3 PARTS LOCATION
POWER SW PCB CONTROL PCB DBX PCB
TIMER
PCB
VOLTAGE
SELECTOR
PEAK
PROGRAM
REC/PLAY
AMPL
PCB
JACK
PCB
LEVEL
METER
UNIT
Fig. 3-1 Top view
LINEAR COUNTER
POWER
SWITCH
PEAK
PROGRAM
LEVEL
METER
COUNTER
PCB
TIMER
SWITCH
“RECORD
CONTROL
SW
PCB
SW
PCB
(MEMORY)
OUTPUT
CONTROL
Fig. 3-2 Front view

V-2RX/V~4RX
RECORD SAFETY SWITCH ' CASSETTE-IN SWITCH
SENSOR ARM SENSOR ARM
R ABLE AK ECUPABE AB
ERASE HEAD REC - PLAY HEAD PINCH ROLLER
Fig. 3-3 Transport front view
CASSETTE-IN SWITCH RECORD SAFETY SWITCH
TAPE SPEED CONTROL REEL MOTOR DAMPER
CAPSTAN MOTOR
PAUSE SOLENOID JOINT PCB PLAY SOLENOID
Fig. 3-4 Transport rear view

-V-2RX/V-4RX
4 MECHANICAL CHECKS AND ADJUSTMENTS
4-1 PLAY SOLENOID
1. With the deck in the play mode, check that the pinch roller is
pressing against the capstan shaft and that the pinch roller arm
spring is released from the pinch roller arm.
2. lf adjustment is required, adjust the position of the play sole-
noid.
capstan shaft
pinch roller
(3
oO
pinch roller >
ge a
arm spring 5
eX
pinch roller arm
Released here
Fig. 4-1
4-2 PAUSE SOLENOID
1. The clearance between the pinch roller and the capstan shaft
should be 0.3mm ~ 0.5 mm when the deck is in the pause
mode.
2. If adjustment is required, adjust the position of the pause sole-
noid.
4-3 TAPE PATH ADJUSTMENT (V-2RX ONLY)
1. Load and play a TEAC MTT-902 mirror tape (C-90) and check
for any noticeable tape curling on the sides of the record-playback
head guide.
2. Adjust the height of the erase head when curling is evident.
3. The clearance between the head base plate and the head stopper
should be 0.3 mm ~ 0.5 mm, as shown in the figure below, when
the erase head is touching the pad holder assembly during play-
back.
pad holder ass’y
2 Head stopper
erase head height pe
adjustment nut
Fig. 4-2
4-4 PINCH ROLLER PRESSURE
1. With the cassette holder shut and no tape loaded, putihe deck in
the play mode after pushing the cassette-in switch senQr arm up-
wards and holding it.
2. Hook a spring scale on the pinch roller assembly as siOwn in the
illustration.
3.. Pull the scale downwards until there is sufficient foie to sepa-
rate the pinch roller from the capstan shaft.
4. Ease pressure until the pinch roller makes just enough contact
with the capstan shaft so that the pinch roller just begins to turn.
At this point, note the reading on the scale. It shoulel be from
350 g to 450 g (12.3 oz. to 15.9 o2.).
Fig. 4-3
4-5 REEL TORQUE
1. Load the cassette torque meter on the deck and read the pointer
indication on the dial scale for each tape transport operation.
The measured torque should be within the following values:
Take-up: 35 to 65 g-cm (0.49 to 0.90 oz-inch)
Supply: 2 to 4.g-cm (0.028 to 0.056 oz-inch)
F.F/REW: 80 to 150 g-cm (1.1 to 2.1 oz-inch)
4-6 TAPE SPEED
1. Connect a frequency counter to the deck as shown in Fig. 4-4.
2. Play a tape for more than five minutes to warm up the deck,
then load a TEAC MTT-111 test tape containing a 3000-Hz test
tone and play the test tape.
3. While the tape is playing, use a non-metallic or insulated screw-
driver and adjust the control on the capstan motor for a reading
of 3015 to 3025 Hz on the frequency counter.
4. Play the tape at the beginning and at the end, and check that the
speed deviation is within the ‘prescribed limits by observing that
the reading on the frequency counter never deviates more than
+70 Hz from 3000 Hz, nor drifts more than 70 Hz at any given
time.
Frequency Counter
Oscillator
Wow &
Flutter Meter
DECK
under TEST
R
LINE IN
(R)
OUTPUT
Fig. 4-4

4-7
WOW
AND
FLUTTER
Note:
These
measurements
should
be
made
at
the
beginning,
middle
and
the
end
of
the
tape.
1) PLAYBACK
1.
Connect
a
wow-and-flutter
meter
to
the
deck
as
shown
in
Fig.
4-4,
2.
Load
and
play
a
TEAC
MIT-1
T1
test
tape.
3.
Check
that
the
reading
on
the
wow-and-flutter
meter
is
within
G.06% (WRMS).
RECORD/PLAYBACK
4.
Load
a
blank
TEAC
MTT-501
test
tape
and
record
a
3000-Hz
signal.
5.
Rewind
the
tape
to
the
beginning
of
the
recorded
section,
and
play
it.
6.
The
wow
and
flutter
should
not
be
more
than
0.25%
(RMS),
No
~~
4-8
LUBRICATION
Lubrication
is
only
required
when
parts
are
replaced.
For
this
purpose,
use
the
oil
and
grease
specified
below.
Oil:
TEAC
spindle
oil
(from
TEAC
TZ-255
oil
kit),
Mobil
D.T.E.
Oi]
Light,
or
equivalent
Grease:
ORE-LUBE
G1/3
or
equivalent
1.
Apply
a
drop
of
oi!
with
an
oil
applicator
to
a
point
about
1/3
the
way
down
the
shaft,
from
the
free
end
of
the
flywheel,
then
insert
the
shaft
into
the
capstan
housing.
2.
Apply
a
suitable
amount
of
light
grease
to
the
well
of
the
flywheel
bearing.
Capstan
flywheel
ass‘y
G ~
capstan shaft
S
well of
flywheel
yy
[
Apply
a
drop
of
oil
here
|
bearing
Capstan
housing
Fig. 4-5
|_V-2RX/V-4RX
4-9
VOLTAGE
CONVERSION
1.
2.
(GENERAL
EXPORT
MODELS
ONLY)
Always
disconnect
the
power
line
cord
before
making
these
adjustments,
Locate
the
voltage
selector
on
the
bottom
side
as
shown
in
the
illustration,
.
Using
a
regular
screwdriver,
turn
the
selector
until
the
numerals
corresponding
to
the
voltage
requirements
of
your
area
appear,
100/120
220/240
Fig. 4-6

_V-2RX/V-GRX |
5
ELECTRICAL
CHECKS
AND
ADJUSTMENTS
PRECAUTIONS :
1. Before performing adjustments and checks, clean and demag-
netize the entire tape path.
2. Make sure the deck is properly set for the voltage in your local-
ity.
3. In general, adjustments and checks are made in the order of
L-ch then R-ch. Double REF. Nos. and test point designations
indicate L-ch/R-ch. (Example: R11/R21)
Oscillator Distortion Analyzer
Attenuator
. 0 dB is referenced to 0.775 V. If an AC voltmeter thi references
0 dB to 1 V is used, appropriate compensation should be made.
. The AC voltmeter used in the procedures must hav@ an input
impedance of 1Mo or more.
. Note the “deck settings” at the top of each chart. The settings
apply to all checks for a specific chart unless explicitly stated
otherwise.
Oscilloscope
AC Voltmeter
1kHz Filter
LINE IN OUTPUT
Fig. 5-1 Basic test setup
Deck settings:
LEVEL cont.: OFF (depressed) .
MONITOR sw TEAC test tapes:
{V-2RX only): TAPE MTT-150: For Dolby level calibration
NR SYSTEM sw: OUT MTT-356: ‘For playback Lh barten 4 response
TAPE sw: METAL check for METAL, Co (CrO2)
5-1 PLAYBACK PERFORMANCE OUTPUT cont.: MAX MTT-501: For S/N check with NORMAL
ADJUST MEASURING
ITEM SETTING INPUT SIGNAL (or CHECK) POINT: RESULT REMARKS
: OUTPUT: Refer to Fig.
. REC-PLAY MEDIC eneee Phase: within 45° 5-5.
head Connection: Fig. 5-2 Azimuth screw | OUTPUT:
azimuth
MTT-356 (12.5 kHz)
of R-P head
(Figs. 5-3, 5-4)
Max. output at L-&
R-ch’s (on VTVM)
. Specified
output
——
level
MTT-150
OUTPUT: Spec. output
R11/R21
~3.5
dB
(518
mV)
level
. PEAK PRO-
PEAK PROGRAM
GRAM LEVEL — MTT-150 R15/R25 LEVEL METER:
METER 0dB
TAPE sw: METAL
If 10 kHz output is lower
then spec, connect C107 MTT-356 Check OUTPUT: Fig. 5-6
(C202) in parallel with C101
(C201) on REC/PLAY AMPL
. Frequency PCB.
response
TAPE sw: NORMAL MTT-356
OUTPUT: At 10 kHz
should be approx.
Check 4 dB higher than
measured in above
step.
F i
Fully-erased
Ratio
of
spec.
.
Signal-to-noise
:
.
OUTPUT:
ratio
TAPE
sw:
NORMAL
MTT-501
tape:
Check
47
dB
min.
outp
ut
of
(Use bulk tape eraser)
-3.5 dB to noise

Deck settings:
eee
LEVEL cont:
MONITOR sw
5-2
MONITOR
PERFORMANCE
OUTPUT
cont.:
V-2RX/V~4RX
REC/PAUSE mode (V-4RX only)
OFF (depressed)
{V-2RX only): SOURCE
NR SYSTEM sw: OUT
MAX
ITEM SETTING
INPUT SIGNAL
ADJUST
(or CHECK)
MEASURING
POINT:
RESULT
REMARKS
MICROPHONE:
400 Hz/-67 dB
(346 pV)
OUTPUT:
~3.5 dB +3 dB
(367 mV ~ 731 mV)
MICROPHONE
min. input
level
6.
Min,
input
level
RECORD
cont.:
Max.
LINE IN:
400 Hz/-19 dB
(86.9 mv)
OUTPUT:
~3.5 dB +3 dB
LINE min.
input level
LINE IN:
400 Hz/-9 dB
(275 mV)
7. Specified LINE
Specified setting
of RECORD
cont.
RECORD
cont. (L/R)
OUTPUT:
~-3.5 dB (518 mV)
Connection:
Fig.
5-7
400
Hz/-9
dB
revel
(275
mv)
DECK
under TEST
OUTPUT
AC
Voltmeter
Fig. 5-2 Test setup for azimuth check
REC - PLAY head
Fig. 5-3 Azimuth screw location (V-2RX)
REC/PLAY head
azimuth
adjusting
screw
fixed
Fig.
5-4
Azimuth
screw
location
(V-4RX)
input level
IMPORTANT:
Do
not
change
the
setting
of
the
RECORD
contro!
after
establishing
the setting as above.
8.
PEAK
PRO-
LINE
IN:
PEAK
PROGRAM
GRAM
LEVEL
400
Hz/-9
dB
LEVEL
METER:
METER
(275
mV)
O
dB
+1
dB
9.
PHONES
output
LINE
IN:
PHONES:
~-15 dB +3 dB
(97.5 mV ~ 195 mV)
0°
(IN
PHASE)
45°
90°
180°
Fig. 5-5 Confirming phase relationship
TAPE sw: METAL
Tape: MTT-356
V-4RXy 43
| +2
a
a,
1
315
(dB)
—3
4
63k 10k (Hz)
Fig.
5-6
Playback
frequency
response
> AC Voltmeter
DECK under TEST
PHONES
Fig.
5-7
Test
setup
for
PHONES
check

V-2RX/V-4RX
LEVEL cont.: OFF (depressed)
MONITOR sw
(V-2RX only): TAPE
RECORD cont.: Specified position (item 7)
NR
SYSTEM
sw:
OUT
TEAC
test
tapes:
BIAS FINE cont. ( ; ) MTT-5072: For METAL recorcel test
(V-2RX
only):
O
(center
detent
position
MTT-5061:
For
Co
(CrO,)
record
test
5-3 RECORDING PERFORMANCE output cont.: MAX MTT-501: For NORMAL record test
ADJUST MEASURING
ITEM SETTING INPUT SIGNAL (or CHECK) POINT: RESULT
Li oy
LINE IN: (V-2RX TP11/TP21
10.BIAS
trap
REC/PLAY
-
REC/PAUSE
No
signal
U104/U204
Min.
reading
(V-4RX)
1) Adjust in the order of steps (2) (3) (4).
LINE IN: C155/C255 OUTPUT:
2) TAPE sw.: METAL 400 Hz & 6.3 kHz (V-2RX) Nearly equal
Tape: MTT-5072 alternately/-42 dB | C131/C231 level at both
:
{6.15
mV)
(V-4RX)
frequencies
2 LINE IN: OUTPUT:
11.
Record
bias
3)
TAPE
sw.:
Co
(CrO,)
400
Hz
&
6.3kHz
|
243
Nearly
equal
..
For
L-
&
Tape: MTT-5061 alternately/-42 dB | © ~ """" level at both R-ch
(6.15
mv)
frequencies
LINE IN: OUTPUT:
4)
TAPE
sw.:
NORMAL
400
Hz
&
6.3
kHz
R12
Nearly
equal
..
For
L-
&
Tape:
MTT-501
alternately/-42
dB
|“
""""
level
at
both
R-ch
(6.15 mV) frequencies
LINE IN:
TAPE sw.: METAL. OUTPUT:
Tape: | MTT-5072 Noe R14/R24 -6.5 dB (367 mV) a
fi LINE IN: OUTPUT:
12.
Record
level
TOEE
Ce
400
Hz/-12
dB
Check
-6.5
dB
#1.5
dB
ee (195 mV) (308 to 436 mv)
2 LINE IN: OUTPUT:
TAPE sw.: NORMAL 400 Hz/-12 dB Check -6.5 dB +1.5 dB
Tape: MTT-501 (195 mv)
13.
Total
harmonic
LINE
IN:
OUTPUT:
“di
torti
Same
as
12
above.
400
Hz/-12
dB
Check
1.8%
or
less
with
METAL,
Co
(CrO2)
eee
(195
mV)
2.0%
or
less
with
NORMAL
LINE IN:
TAPE sw.: METAL . i OUTPUT:
Tape: MTT-5072 dicta aol al Fig. 5-8
LINE IN:
14.
Frequency
TAPE
sw.:
Co
(CrO,)
s
-
OUTPUT:
response Tape: MTT-5061 Se ew Check Fig. 5-9
:
LINE
IN:
:
Me owe belles Required signal/ Check ein E18
pens -42 dB (6.15 mV) a
If frequency response is out of specification, recheck #11. ‘Record bias’.
LINE IN:
400 Hz/-9 dB
TAPE
sw.:
METAL
OUTPUT:
Tape: MTT-5072 (275 ee Gheck 46 dB min.
no signal
LINE te eee
‘ ‘
400
Hz/-9
dB
atio
of
spec-
15.
Signal-to-noise
TAPE
sw.:
Co
(CrO,)
OUTPUT:
gs
ratio
Tape:
MTT-5061
oN
Check
46
dB
min.
ieeeu
anaes
no signal
. LINE IN:
400 Hz/-9 dB
TAPE
sw.:
NORMAL
OUTPUT:
Tape:
MTT-501
aim
neal
45
dB
min.
no signal
(2.
10