Teac A 3440 Service Manual

Page 2

The TEAC A3440 is a

The A-3440 is a development 0
the transport section is virtually the s
electronics The FUNCTION SELECT switches, togct

instant selection of so
RX-9 DBX noise redu

ction uni

noise performance of the deck,

The A3440 is ideally suited to t

If any of the procedu

res in this manUal are not su
suggest you contact your nearest TEAC Factory Service Department or write directly to the TEAC Corpo-

rations TEAC addresses are printed on the back cover of this manual

ame though there

he requirements of the musi

4 channel, multi-track open reel tape

t" the well known A334OS and shares many features in common. Specifically,
has been extensive redesign of the controls and the
her with the OUTPUT SELECT switches provide
urce, sync and normal off-tape monitoring. There is a rear panel interface for the
T which will greatly improve the dynamic range and signal to

cian and multi-track recordist.

fficiently clear, or seem too difficult to undertake, we

deck which operates at 15 ips and 7-1/2 ips.

- TABLE OF CONTENTS -
l. GENERAL DESCRIPTION ................ 3
2, SPECIFICATIONS AND SERVICE DATA ..... 4
3. TOOLS FOR TESTING AND MAINTENANCE . 5
4. PARTIAL DISASSEMBLY ................ 6
5. TAPE TRANSPORT PARTS LOCATION ...... 9
- Rear View -
6. HEAD REPLACEMENT AND ALIGNMENT . . r l()
- Mechanical -
7. MEASUREMENT AND ADJUSTMENT ....... l2
- Mechanical -
8. MEASUREMENT AND ADJUSTMENT ....... l6
- Electrical -
9. SERVICING AND MAINTENANCE ......... 23
10. SIMPLIFIED SCHEMATIC AND LEVEL
DIAGRAMS ........................ 24
ll, TEAC DECIBEL TABLES ................ 25

Page 21

12-SlMUL-SYNC PERFORMANCE

12-1 SYNC PLAYBACK LEVEL

OUTPUT SELECT SW ......... SYNC

. Connect a VTVM to the OUTPUTjack.

. Play the 400 Hz 0 dB tone in section 1 of the YTT-1003
Test Tape.
. Check for -8 dB :1 dB (356 mV - 275 mV) at the

OUTPUT jack.

12-2 SYNC FREQUENCY RESPONSE

4.

"57m. ... n.

- PLAYBACK-

Apply a signal swept from 50 Hz to 6.3 kHz at -12 dB
(195 mV) and while monitoring the off-tape signal check
for readingswithin the Response Limits.

HIGH (ISiDSl

LOW (7- 1/2 ups)

mm

"(0qu .1. N.

Fig. 8-15 SYNC Freq. Response

12-3 SYNC S/N RATIO CHECK

}
l.

OUTPUT Level Control should be at the Specified Out-
put Level Setting.

2. Remove the Test Tape from the deck. Hold the shut-
off arm (right) in the ON position.
3. Press the PLAY (>) button.
4. The VTVM connected to the OUTPUT jack should in-
dicate the values below.
OUTPUT SELECT SW Tape Speed S/N
7-1/2ips -48 dB
SYNC 15 ips -48 dB

NOTE: This corresponds to a signal-to-noise ratio of 40 dB

(for SYNC 7-1/2 ips). It is the difference between
the residual noise of -48 dB and the specified out-
put level -8 dB.

22

12-4 SYNC CHANNEL SEPARATION

TAPE SPEED SELECTOR SW HIGH (15 ips)
FUNCTION SELECT SW ......... all 0N

. Repeat the page 21, item 117 procedure and check the

crosstalk in the SYNC mode. The level should be --53
dB or better (spec. 45 dB).

12-5 SYNC CROSSTALK CHECK

1.

Apply a 2 kHz ~12 dB (194 mV) signal from the AF
oscillator to the LINE lencks 1,3 and 4.

. Place the deck in the REC and PAUSE mode.
. Ensure that the FUNCTION SELECT SW for channel 2
is OFF.

. Check the difference in level between the Sync output

(1,3 and 4) and (2).
The difference should be 8 dB or less.

. Repeat these procedures for channels (1,2 and 4) and

between 3.