Teac X-7RMKII User manual

TEAC.
SERVICE MANUAL
X-FR oll X-Fi
Stereo Tape Deck

X-7R oO /X-7ucl
1 SPECIFICATIONS AND SERVICE DATA
SPECIFICATIONS
Track System %-track, 2-channel stexeo
Head System
X-7RMKII: 6 heads: forward erase, forward record, reverse
playback, forward playback, reverse
record, reverse erase.
X-7MKII: 3 heads: erase, record, playback
Reel Size 7”
Tape Speed 19cm/s (7-% ips) and 9.5cm/s (3-% ips)
Inputs (level and impedance)
MIC: Specified input level: —G0dB (0.775mV)/10kohms
Min. input level: ~70dB (245nV)
LINE IN: Specified input level: —12dB (195mV)/50kohms
Min. input level: —22dB (61.5mV)
Outputs (level and impedance)
OUTPUT: Specified output level: —5dB (436mV)/10kohms
Max. output level: +1dB (0.869V)
PHONES: Specified output level: —24dB (48.9mV)/8o0hms
Playback Equalization
19em/s: 3,180us + 50us (NAB), 3,180us + 35ys (EE)
9.5em/s: 3,180us + 90us (NAB), 3,180us + 50us (EE)
Motors
Capstan motor: DC brush motor with FG servo
Reel motor: 2 DC slotless motors
Bias Frequency 100kHz
Operating Position Vertical, horizontal, angled
Power Requirements
100/117/220/240V, AC 50/60Hz, 77W, 72W for X-7MKII
(General export model)
220V AC 50Hz, 77W, 72W for X-7MKI (Europe model)
240V AC 50Hz, 77W, 72W for X-7MKI] (U.K./Australia model)
117V AC 60Hz, 77W, 72W for X-7MKII (U.S.A./Canada model)
Weight 18kg (38-11/16 Ibs.) net
aera rt
196mm
(7-3/4)
270mm ___|
(10-5/8"')
h——— 461mm (18-3/16'") —-—
454mm(17-7/8"")
384mm(15-1/8"") ——+]
411mm(16-3/16"") ——
—) Saad
OO
co Oe
+-—— 369mm(14-9/16"")
=
Dashed line indicates General Export Models for Limited Areas.
Fig. 1-1 Dimensions
SERVICE DATA
MECHANICAL
Tape Speed Deviation 3,000Hz + 30Hz
Tape Speed Drift 15Hz
FWD/RED Tape Speed Differential (X-7RMKII only) 30Hz
Wow and Flutter
Playback: 0.05% (WRMS), 0.10% (RMS) at 19cm/s
0.07% (WRMS), 0.12% (RMS) at 9.5cm/s
Record/Playback: 0.12% (RMS) at 19cm/s
0.15% (RMS) at 9.5cm/s
Pinch Roller Pressure 1.35kg ~ 1.9kg (3.0 Ibs ~ 4.2 Ibs)
Reel Torque
Play mode:
Take-up 260 + 40g-cm (3.1 ~ 4.20z-inch)
Back tension 180 + 40g-cm (1.9 ~3.10z-inch)
Fast winding mode:
Take-up: 1100g-cm (15.30z-inch)
Back tension: 50g-cm (0.70z-inch)
Brake Torque
Forward direction: 800 ~ 1400g-cm (11 ~ 190z-inch)
Reverse direction: 500g-cm (6.90z-inch) or less
Left/right deviation: 200g-cm (2.80z-inch) or less
Fast Winding Time 150 seconds or less for 550m (1800 feet)
Pitch Control Standard tape speed +6% or more
FWD/REV Change Time (X-7RMKII only) 3.5 sec. +0.5 sec.
TIMER Activate Time 4 sec. +2 sec.
ELECTRICAL
Frequency Response Playback: See Fig. 3-5 to 3-6
Overall: See Fig. 3-7 to 3-8
Signal to Noise Ratio Playback: 50 dB min. (19 cm/s, LH)
52 dB min. (19 cm/s, EE)
49 dB min. (9.5 cm/s, LH)
52 dB min. (9.5 cm/s, EE)
48 dB min. (19 cm/s, LH)
50 dB min. (19 cm/s, EE)
46 dB min. (9.5 cm/s, LH)
50 dB min. (9.5 cm/s, EE)
68dB min. at 1kHz (measured with input
10dB higher than the specified input level)
Channel Separation 50dB min. at 1kHz
Adjacent Track Crosstalk 40dB min. at 125Hz <
Total Harmonic Distortion 0.8% or less at 1kHz
Overall:
Erase Efficiency
e Improvements may result in SPECIFICATIONS AND SER-
VICE DATA changes.
e Value of “dB” in the data refers to OdB (0.775V), except
where specified.
AParts marked with this sign are safety critical components.
They must always be replaced with identical components —
refer to the TEAC Parts List and ensure exact replacement.

X-7R vc D/X-7ucll
2 MECHANICAL ADJUSTMENTS AND CHECKS
NOTE: All the explanations are for the X-7RMKII. But unless specified they can also be applied to the
X-7MKIL except for those in relation to the REVERSE direction.
2-1 CONTROL PCB ASSY CHECK
Hooking CONTROL PCB ass’y as shown facilitates this check.
CONTROL PCB ass’y
TA-1030
Fig. 2-1
2-2. BRAKE ADJUSTMENT
NOTE: The explanation and figure in this paragraph are for the left
side brake, similar checks and adjustments are applicable
for the right side one.
1. Adjust by moving the brake band bracket in either direction
(arrow (A)) so that the reel motor chassis is in parallel with the
brake arm, and so that the brake band makes proper clearance
equally all around the reel table base.
2. Adjust by moving the brake solenoid in either direction (arrow
(D)) so that the stroke of the solenoid plunger is about 2mm.
3. Adjust by moving the band ass’y retaining plate as shown in (B,
C, E) so that, when the plunger is pushed in the direction of the
solenoid housing, the reel table base is not rubbed by the brake
band and is properly spaced.
solenoid plunger
reel motor chassis
N :
@ G zk, pang
KP agar we
brake arm
brake band
brake solenoid
solenoid mounting screws
ve band ass’y retaining plate
TA-103
Fig. 2-2
2-3 BRAKE TORQUE MEASUREMENT
1.
Place
an
empty
7”
reel,
connected
to
a
spring
scale
by
a
string,
on
the
reel
table.
2.
Pull
the
scale
away
from
the
reel
and
read
the
scale
indication
only when the reel table is steady motion.
3.
Do
steps
1
and
2
for
each
measuring
condition,
(A)
through
(D)
in
Fig.
2-3.
4. The values are as chart in Fig. 2-3.
>
tee]
spring scale
----
—c—
——
1
' ' force
Ss oh 3 X\]
Cham
?
TA-1032
Forward
direction
(B)
(C)
|
800
to
1400g-cm
(11
to
190z-inch)
Reverse
direction
(A)
(D)
|
500g-cm
(6.90z-inch)
or
less
Left/right
deviation
|
200g-cm
(2.802-inch)
or
less
NOTES: 1. The reverse direction values are reference.
2. The specification of left/right deviation only applies
for forward direction torques.
Torque calculating formulas:
(1) Torque (in g-cm or 02-inch)
= Force or Weight (in g or oz) x Radius (in cm or inch)
(2) Conversion of g-cm to oz-inch:
g-cm x 0.0139 = oz-inch
Fig. 2-3

X=7R uD X-7ux
2-4 REEL MOTOR TORQUE MEASUREMENT
1. Hold both left and right tension arms in the upper position
using rubber bands.
2. See Fig. 2-4, Measure torques for each operating mode with the
conditions specified in the chart.
3. Since all the torque values are reference values, it is allowable
that the take-up torque during the fast forward or rewind mode
is tkg-cm or more, and that the back tension torque during
these mode is good unless the left or right tension arm are shut-
off.
4, There is no specially provided adjustment, so if any torque cor-
rection are needed, repair or replace defective part(s) and/or
circuit(s).
i Cc D
q : t
spring scale |
—_—~ > ——_—_ ow
radius
TA-1033
Reel torque reference value
Play mode
Mode Torque
Take-up:
(B) in REV 260 + 40g-cm (3.1 ~ 4.20z-inch)
(D) in FWD
Back tension:
(A) in FWD 180 + 40g-cm (1.9 ~ 3.10z-inch)
L (C) in REV
Fast winding mode
Mode | Torque
Take-up: (B) in REW, (D) in F.F. 1100g-cm (15.30z-inch)
Back tension: (A) in F.F., (C) in REW | 50g-cm (0.70z-inch)
NOTE: For torque calculation, refer Fig. 2-3.
Fig. 2-4
2-5 PINCH ROLLER PRESSURE STROKE ADJUSTMENT
1. Set the deck in the forward or reverse play mode.
2. Adjust by turning the pressure storke adj. nut (Fig. 2-5) so that
the clearance between the pin and the stopper cushion is about
1.0mm.
3. Since the clearance is produced at one side (left or right), ad-
justment for this side only is permissible.
= d
_ P
= se 7
Top Panel
Fig. 2-5 Pinch roller pressure stroke adjustments
left capstan right capstan
teft right
pinch roller pinch roller
if m
@ © AS 7 ue TA-1035
stopper cushions
about 1.0 mm
Either the left or right should have a clearance of about
1.0mm.
Fig. 2-6
2-6 PINCH ROLLER PRESSURE MEASUREMENT
NOTES: 1. The explanation below applies to both the left and
right pinch rollers,
2. Both pinch roller pressures are automatically set with
equal value.
1. Hold both the left and right tension arms in the upper positions
using rubber bands, string etc.
2. Set the deck in either play mode with no tape loaded.
3. Attach the spring scale to the pinch roller as shown in the
figure.
4. Draw the pinch roller away from the capstan shaft (in the
direction of a line intersecting the centers of the capstan shaft
and the pinch roller) until the capstan shaft and the pinch
roller are separated.
5. Return the scale back until the pinch roller just begins to turn.
The scale should then be reading as follow.
Reference value: 1.35kg to 1.9kg. (3.0 Ibs to 4.2 Ibs)
6. If the reading is out of specification, replace defective part(s).
There are no adjustable parts.

spring scale
TA-1036
Fig. 2-7
2-7 TENSION ARM HEIGHT ADJUSTMENT
1. Thread any standard tape on the deck using a standard empty
reels such as TEAC RE-702.
2. Set the deck in the forward or reverse play mode.
3. Stop left (right) guide roller’s rotation by hand. Adjust by
turning the left (right) tension arm adjusting nut (refer Fig.
2-8) so that the tape moves in the center of the guide roller.
right tension arm spring
spring hook
capstan motor
X=7RcO/X-7vcll
4.
Release
the
guide
roller.
Fine-adjust
the
adjusting
nut
again
until
there
is
no
tape
curling
at
the
tape
guide
pin
between
the
erase
head
and
the
left
(right)
guide
roller.
5,
After
adjusting
the
height
of
both
left
and
right
tension
arms,
check
that
the
tape
running
condition
is
good
by
repetition
of
fast
forward
and
rewind
modes.
6.
If
the
tape
running
position
is
different
when
the
guide
roller
stops
and
when
it
turns,
the
condition
when
the
guide
roller
is
rotating
has
priority.
2-8
TENSION
ARM
FORCE
ADJUSTMENT
NOTE:
The
description
below
applies
to
both
left
and
right
sides.
1.
Check
the
shut-off
switch
operates
correctly
with
the
deck
in
the
horizontal
and
vertical
positions.
2.
Adjustment
can
be
done
by
changing
the
hooking
position
of
the
tension
arm
spring
against
the
spring
hook.
2-9 DAMPER FUNCTION CHECK
NOTE:
The
explanation
below
applies
to
both
left
and
right
sides.
1,
Check
that
the
damper
string
begins
to
function
after
the
tension
arm
has
moved
10
to
15mm
from
the
lowest
position,
while
the
damping
function
is
working,
there
is
a
feeling
of
resistance,
2.
Check
that
the
tension
arm
returns
freely
from
the
above
posi-
tion
to
the
lowest
position.
left tension arm spring
shut-off switch spring Deo
damper string
right tension arm
right tension arm adj. nut
TA-1037
damper string
a
left tension arm
ZY
secre
aster
slower
left tension arm adj. nut
Fig.
2-8
Tension
arm
height,
tension
arm
force,
damper
function,
and
tape
speed
2-10 REEL TABLE HEIGHT ADJUSTMENT
1. Adjust the tension arm height beforehand. (See 2-7)
2. Check each reel table height using a TEAC RE-702 empty reel
and letting the tape run in each tape operating mode.
3. If the tape rubs against the ree! flanges, adjust the reel table
height by means of the two reel table mounting screws.
standard empty reel
&
=
Seas
\ Glyn
reel table
Ta- 1038
Fig. 2-9

X-7RuW/ X-7ucll
2-11 REVERSE SOLENOID ADJUSTMENT
(X-7RMKII ONLY)
1. When the reverse solenoid releases, if the slide plate hits the
stopper screw/s noisily, the solenoid stopper plate may be ad-
justed in the direction of the solenoid housing. See illustration.
Parts below are accesible from the rear of the amplifier
chassis.
Loosen
slide plate
solenoid
stopper
plate
stopper screws
BEFORE
reverse solenoid
Fix after adjustment
TA-1039
—_ 0.5 mm max.
Adjustment range is 0.5mm max. in solenoid-off condition.
Fig. 2-10
2-12 ROTATING PART THRUST CLEARANCE CHECKS
Reference values
Capstan shaft: 0.1mm to 0.25mm (magnefloat type)
Guide roller: 0.05mm to 0.3mm
Tension arm guide roller: 0.05mm to 0.3mm
Reel motor: 0 (spring type)
Tension arm: 0 (spring type)
NOTE: Since the capstan shaft is a magnefloat type, check that it is
forced towards the rear of the deck while rotating.
2-13 CAPSTAN MOTOR REPLACEMENT
7. When the capstan motor is replaced, install it with its lead
wires and washers as shown.
2. Check that, when the deck is operated by repeating the forward
and reverse play modes, the capstan drive belt changes position
on the flywheels smoothy.
Fig. 2-11
2-14 TAPE SPEED ADJUSTMENT
FREQUENCY COUNTER
OSCILLATOR
DECK
under TEST
LINE IN
iw
T.403
Fig. 2-12
NOTES: 1. Conduct all the following in both forwar and reverse
play modes.
2. When ordering test tapes, allow for the longer delivery
time that is required for them.
1. Connect a frequency counter to either OUTPUT terminal.
2. Load a TEAC YTT-2003 test tape. Set the SPEED switch—
HIGH, and PITCH CONT knob-OFF.
3. Play the tape. Adjust R18 (see Fig. 2-8) for a reading of 3,000
Hz +5Hz,
4, Check the following at the beginning and the end of the tape.
Specifications:
Tape Speed deviation.............0. 3,000Hz +30Hz
Tape speed drift... . 0... 0... ee eee ee eee 15Hz
FWD/REV tape speed differential . .30Hz(X-7RMKII only)

5. Change the test tape toa TEAC YTT-2002, and SPEED switch
setting to LOW.
6. Repeat steps 3 through 4. Adjust R17 if necessary.
7. Pull the PITCH CONT knob out. Set SPEED switch HIGH.
Play a YTT-2003 tape.
8. Check if the speed variation of at least 3,000Hz +180Hz is ob-
tained when the PITCH CONT knob is rotated fully in both
directions.
9. Change the test tape to YTT-2002, SPEED switch setting to
LOW. Repeat step 8.
2-15 WOW AND FLUTTER CHECKS
NOTES: 1. All the following apply to both forward and reverse
play modes.
2. The following measurements should be made at the
beginning and the end of the tape.
3. When ordering test tapes, allow for the longer delivery
time that is required for them.
Playback
1. Connect the test equipment to the deck as shown in Fig. 2-12.
2. Load and play a TEAC YTT-2003 test tape for HIGH speed
(19cm/s or 7-% ips), or a TEAC YTT-2002 test tape for LOW
speed (9.5cm/s or 3-% ips).
3. Read the indication on the wow and flutter meter.
Specifications:
HIGH speed: 0.05% WRMS
0.10% RMS
LOW speed: 0.07% WRMS
0.12% RMS
Overall
4. Load a TEAC YTT-8013 test tape (blank). Apply and record a
3,000Hz signal. ‘
5. During simultaneous tape monitoring (playing) the recorded
signal, read the wow and flutter meter display.
Specifications:
HIGH speed: 0.12% RMS
LOW speed: 0.15% RMS
X=7R vx D/ X-Fi
2-16 VOLTAGE CONVERSION
(FOR GENERAL EXPORT MODELS)
Always
disconnect
the
power
line
cord
before
making
these
adjust-
ments,
Frequency Conversion
Since
the
X
series
uses
DC
motors,
frequency
conversion
is
not
necessary.
Voltage Conversion
1.
First
remove
the
two
feet
by
removing
the
screws
in
each
one.
2. Unscrew the left and right sides of the cabinet.
3.
Locate
the
voltage
selector
to
the
right
of
the
power
trans-
former
as
seen
from
the
rear
of
the
deck.
4,
Turn
the
slotted
center
post
of
the
selector
with
a
screw-driver
until
the
desired
voltage
numerals
appear
in
the
cut-out
section
of
the
selector.
5. Replace the cabinet and feed.
Om
Fig. 2-13
NN
2-17, LUBRICATION
Oiling is needed after every 1,000 hours of operation or once a year
if the deck is infrequently used. For this purpose, TEAC spindle oil
(from TEAC TZ-255 oil kit), Mobil D.T.E. Oil Light, etc are re-
commended. Lubrication is normally not necessary except at the
points shown.
1. Place the deck in the horizontal position.
2. Apply a few drops of oil to the respective spindles shown, ex-
cluding capstans, then spread the oil evenly on the spindle sur-
faces using a cotton cloth, etc.
3. For capstans, apply a few drops to the indicated position.
4. After oiling all the points, leave the deck for 1 to 2 hours until
the oil is thoroughly absorbed.
Figure shows left side. Do also for right side.
tension
roller
guide
roller
pinch
roller
S
oP
capstan

X=7R vc / X-Fi
2-18 HEAD AND TAPE PATH ALIGNMENTS
NOTES: 1. Head and tape path alignment are the same for the Head adjustment screws
X-7RMKLI. and X-7MKII. The procedure for the X-
7RMKIL
is
given
below
Erase
Record
and
playback
2.
For
detailed
alignment
principles,
refer
to
the
book
Fixed
screws
@
Azimuth
“Audio Fundamental -TAPE DECK-, 8. Mechanical (not adjustable) © Height and tilt
Adjustments” published by the TEAC CORPORA- ® Tangency
TION.
2-18-1 HEAD ARRANGEMENT (for X-7RMKI)
eS oo 28
58S
Oo Oo eo Q
Tape guide pin adjustment nut
Forward Forward Reverse Forward Reverse Reverse
Erase Record mp. Playback Playback _9 Record Erase
Tape guide pins
Fig. 2-15 Head arrangement
2-18-2 HEAD REGULATION ELEMENTS 2-18-3 ALIGNMENT PROCEDURE (for X-7RMKII)
1. Visually adjust the tilt of each record and playback head so
that the head surface is parallel to the nearest tape guide pin.
2. Make coarse azimuth adjustments for the record and playback
heads by viewing each head from in front (without tape).
3. Running a TEAC YTT-8013 test tape (thickness = 35 wm) in
the forward direction, fine-adjust the height of the left tention
Adjust each head to satisfy each of the following:
TILT
The head surface should be parallel to the tape
guide pin surface.
za
AZIMUTH
roller
so
that
the
lower
edge
a
the
tape
is
just
touching
ie
. Parar Gittins lower edge of the tape guide pin (1), See Fig. 2-17, then adjust
The gap of the head core should be perpendicular «=z | : eee
to
the
tape
travel
:
Cl
the
height
of
the
tape
guide
pin
(2)
so
that
the
upper
edge
of
;
the
tape
is
in
contact
with
the
upper
edge
of
the
tape
guide.
HEIGHT
Confirm
that
the
adjustments
do
not
cause
the
tape
to
curl.
—!
—
4.
Confirm
that
the
forward
erase
head
core
protrudes
0.1
mm
The upper (lower) core of the head should be level Bae . :
:
—
above
the
moving
tape.
if
not,
replace
the
head
with
another
with the upper (lower) edge of the tape.
L_ | one and recheck.
TENOENE
Te
ou
yyee
a
me
fag
nae
The dotted line should be perpendicular to the ae: ore aad a clade pay :
surface of the tape.
Fig. 2-16 Head regulation elements

X=7RvcD/ X-7vcll
8.
Loosen
the
two
screws
holding
the
reinforcement
plate,
then
adjust
using
the
correction
jig
(TEAC
P/N
5736000100)
as
shown
in
Fig.
2-19.
Note:
(1)
Use
the
jig
as
near
as
possible
to
the
pinch
roller
spindle.
(2)
Do
not
touch
the
surface
of
spindle.
(3)
Use
no
other
tool
for
this
adjustment!
Fig. shows the forward erase head.
Slight space
Correction jig (TEAC P/N 5736000100)
«< *
y| im
Correction jig
Reinforcement plate screws
Tape
guide
pin
(1)
Forward
erase
head
intor
p
NOTE:
In
the
case
of
the
reverse
erase
head,
the
tape
should
be
in
contact
with
the
lower
surface
of
the
Reinforcement
plate
tape guide pin (4).
Fig. 2-17 Erase head height
Pinch roller
spindle
6. Check for any tape curling at either tape guide pin in the
closed loop portion of the tape (i.e., between the capstans).
7. If there is any tape curling at tape guide pin (2) during forward
play, do the following: Unthread the tape from the front of
the head assembly. Remove both pinch rollers. Set the deck in
the play mode. Then visually align the pinch rofler spindle with
the capstan as described below.
Fig. 2-19 Pinch roller/capstan alignment
Fig.
shows
left
side.
9.
If
the
tape
curls
at
tape
guide
pin
(3)
in
reverse
play,
correct
in
the same way (steps 7 and 8). .
10.
After
it
is
entirely
corrected
that
there
is
no
tape
curling
condi-
tion
in
the
head
assembly,
fine-adjust
each
record
and
playback
height
so that
the
brass-colored
spacer
of
forward
(reverse)
Pinch roller spindle is tilted to the left
Left pinch roller +
Tape curling
direction purpose head will show above (below) the moving
spindle
Left
capstan
: .
—
.
observed
here
tape.
(About
as
thick
as
a
thin
pencil
line).
Adjustment
should
in
the
forward
be
done
by
equally
turning
three
screws
required
correction
Tape
|
|
|
|
play
mode.
not
to
disturb
tilt
and
azimuth
regulation
conducted
before.
11.
Finally,
if
necessary,
make
rough
tangency
adjustment
of
re-
spective
head
with
tape
running.
Forward record head
Tape guide pin (2)
If
the
pinch
roller
spindle
is
tilted
to
the
left
(right)
with
respect
to
the
capstan
shaft,
tape
curling
may
occur
at
the
upper
(lower)
edge
of
the
tape
guide
pin
(2).
Fig.
2-18
Example
of
improperly
aligned
pinch
roller
and
capstan

X=-7R oc O/X-Aucll
3 ELECTRICAL ADJUSTMENTS AND CHECKS
ADJUSTMENT AND TEST POINT LOCATIONS
tours of
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R501/R601 Playback level (FWD) R514/R614 Record level (FWD)
R502/R602 Play back level (REV) R513/R613 Record level (REV)
R503/R603 Playback EQ (HIGH FWD) | R516/R616 Record Bias EE (FWD) 4
R504/R604 Playback EQ (HIGH REV) R515/R615 Record Bias EE (REV)
| R505/R605 Playback EQ (LOW FWD) | R517/R617 Record Bias LHI (FWD)
R506/R606 Playback EQ (LOW REV) R518/R618 Record Bias LHI (REV)
R507/R607 Output level L102/L202 Bias trap (record)
R508/R608 VU meter (playback) L £103/L203 Record EQ (FWD)
i R509/R609 |___VU meter (monitor) j___ £104/L204 Record EQ (REV) _|