Teac A 7010 GSL 7030 GSL Service Manual

Page 2

l . GENERAL DESCRIPTION

The TEAC A-703OGSL has a heavy duty transport mechanism; three motors,
solenoid operated, four high density ferrite heads provided (erase,
record, playback and reverse playback); dual system automatic reverse,
phase sensing signal or foil operated; 10-1/2 inch reel capacity, reel
size selector provides optimum tape tension.

The AR-70GSL preamplifier circuits use IC and silicon transistors.
Independent circuits are provided for recording, monitoring, VU meter
amplifier and playback functions. Electrical assembly provides two
level bias selection for conventional and low noise/high out tapes,
dual scale VU meter, meter level switch for optimum recording accuracy
with any type recording tape; full MIC/LINE mixing capability with
indivudual mic/line amplifiers and indivudual level controls.

The basic design of the A-7OSOGSL is highly similar to the preceding
Ar703OGSL model. The A-7030GSL is a professional tape deck offering
operating speeds of 7-1/21ps and lSips. Normal head configuration is
two track record and playback with an extra four track playback head.
Sensing foil operated automatic rewind or stop operation is included.
Incorporates all electrical assembly feature of the A-7010GSL excep-
tion equalization is for 7-1/Zips and lSips tape speed.

The service manual provides adjustment and alignment procedures,
schematic diagrams and parts replacement information with the proper
procedures for obtaining necessary repair parts.

If adjustments or repair procedures are not clear or seem difficult to
accomplish or should you desire more detailed technical information,
please contact your nearest TEAC dealer, TEAC Corporation or affiliat-
ed corporations, addresses of which are printed in this manual.

IFdEJE)(

I. GENERAL DESCRIPTION
2. SERVICE DATA
3. EQUIPMENT REQUIRED
4. PARTIAL DISASSEMBLY
5. HEAD MECHANICAL ALIGNMENT
6. MEASUREMENT AND ADJUSTMENT
-MECHANICAL-

7. MEASUREMENT AND ADJUSTMENT

' -ELECTRICAL-
8. PREVENTIVE MAINTENANCE
9. TROUBLE SHOOTING CHART
IO. SCHEMATIC DIAGRAM
TI. PRINTED CIRCUIT BOARD AND PARTS LIST
12. EXPLODED VIEW AND PARTS LIST
T3. WARRANTY AND PACKING FOR SHIPMENT
T4. MANUAL CHANGE

Page 18

OVERALL FREQUENCY RESPONSE AND THE RECORDING EQUALIZATION ADJUSTMENT

IMPORTANT: To avoid saturation of the tape, these checks should
be made at least 15 dB below the specified input level. Any bias
signal feeding into the test equipment should be filtered out by
adjusting the external bias trap. A broad band VTVM may be used
on the output of the unit for this adjustment.

With the MONITOR switch at TAPE, and the OUTPUT and LINE controls
at their specified level position:

Place BIAS,EO/LEVEL switch in HIGH position, thread Scotch 203
record test tape on the unit.

Record test signals(approximately 30 seconds each)of a variety of
frequencies: 50, 100, 250, 400Hz; 1, 2.5, 5, 7.5, 10, 15, 20 kHz
at 7-1/2ips or lSips.

Repeat step 3 at 3-3/4ips with frequencies from 40 Hz to 10 kHz.
Compare the outputs with the frequency response chart in figure.
The level variation should not exceed i0.5 dB at the 400 Hz ref-
erence point, $1.5 dB at 15 kHz. At 3-3/4ips, you may see up to
:2 dB at 10 kHz.

If adjustment is required, adjust L-102/202 at 7-1/2ips (on the
A-7030GSL, 15ips). If the coil adjustments do not bring the
response within limits, then adjust C-140/240 at 7-1/2ips(on the
A-7OBOGSL, lSips), and C-lAl/241 at 3-3/4ips (on the A-7OBOGSL,
7-l/2ips)[ Make these adjustments so that you obtain the most
level response across the spectrum in reference to 400 Hz.
Repeat steps 3, 4 and 5 with Scotch 150 tape and set the BIAS
switch to NORMAL position. Response should be flat as shown
before the dotted portion of the chart.

assmuse m an

FREQUENCV m m

Fig. 7-12 Frequency Response Limits -Récord-

Page 45

EXPLODED VIEW AND PARTS LIST 10

ArlOIOGSL A-7oaocsn.

LEFT TENSION ARM

.(um

\

REVISION
REF . TEAC
N0 . PARTS N0 . DESCRIPTION 151: 2nd
10- 1 50183021 Tension Arm, L
10- 2 50182870 Bushing, Tension Arm L
10- 3 50453160 Terminal Strip
10- 4 50181360 Pin, Limit Stop
10- 5 50111710 Bracket, Limit Stop
10- 6 50277620 Cushion, Rubber
10- 7 50182140 Washer, Thrust
10- 8 50221200 Washer, Thrust
10- 9 50277390 Nut
10-10 50180620 Left Tension Arm Sub (C) Assy
10-11 50123140 Pin, Spring Retainer
10-12 50277400 Vinyl Tube
10-13 50220030 Spring, Tension Arm

20

Page 46

fl

EXPLODED

RIGHT TENSION ARM

VIEW AND PARTS LIST 11

A-IOIOGSL A»1osoesL

(A-7030GSL)

REVISION
REF. TEAC
NO. PARTS NO. DESCRIPTION 15: 2nd
11- 1 50182941 Tension Ann, R (A-70lOGSL)
50182981 Tension Arm, R (A-7030GSL)
ll- 2 50181920 Bushing, Tension Arm R
11- 3 50272951 Bracket, Micro SW
11- 4 50446180 SW, Micro
11- 5 50272940 Bracket, Magnet
11- 6 50183900 Magnet
11~ 7 50182140 Washer, Thrust
ll- 8 50221200 Washer, Spring
11- 9 50277412 Arm, Micro SW Actuator
' 1141077" 57017823171:"éiringffféhsi/onKid R '
11-11 50141561 Limit Stop, Tension Arm R
11-12 50182950 Cushion, Rubber
11-13 50182360 Guide, Tape
11-14 50182340 Post, Tape Guide, L
11-15 50180630 Right Tension Arm Sub (C) Assy
(A-7010GSL)
50180640 Right Tension Arm Sub (C) Assy