Teac AN 180 Service Manual

Page 1

TEAC 48°

'fThe- TEAC AN~180 is a noise reductlon unit employing the DOLBY E
,Lsystem. The unit comprises Independent playback, recorE (seif-5 . In
jcontalned microphone ampllfler), meter- amplifler and5 oscillator E5ggg.
5 ' cxrcuits¥ all utzlizing sach new solld~state circuit elemen 5'5
",as 1-65 n 3FEEE " I -

' actically no recalibration exeept after the replacement
A ., ;._ApQ ents.. This manual describes mainly for thé benefit oE
',flgservice engineers, .the specifications, aéjiustment and teéting
/-\ v.1fVL5proceéures, trouble-shooting and Circuit diagrams of the .AN-180.
5 ~ } MExplanations which duplicate thOSe in the instruttion manual v
_'54 fhave been omittéd. Pleasé .refér to the latter. concerning han~ 5
55gngling and operatlon AI -

[A
TEAC CORPORATION U.s. DISTRIBUTOR: TEAC CORPORATION OF AMERICA
7733 TELEGRAPH ROAD
SALES OFFICE: SHINJUKU BUILDING MONTEBELLO, CALIFORNIA 90640
1-8-1, NISHI-SHINJUKU, SHINJUKU, TOKYO u.s.A.
TEAC HONGKONG LIMITED Room NO. 1105 EUROPEAN DISTRIBUTOR: TEAC EUROPE B.V.
/ MAIN OFFICE: MELBOURNE PLAZA, 33 QUEEN'S ROAD KABELWEG 45-47, AMSTERDAM-W 2.
CENTRAL, HONG KONG HOLLAND
A

MA1800E300 PRINTED IN JAPAN 0173 SYUO2

Page 5

TESTING PROCEDURE

REQUIRED TEST EQUIPMENT

This chapter systematically describes the testing procedures for
the playback section, recdrding section and multiplex filter.
Since all these sections interact with each other, pay special
heed to the sequence of the testing procedures.

1. Oscillator output level test

. Level meter sensitivity test
Overall characteristics test
Playback characteristics test
. Recording characteristics test
. Multiplex filter test

GUI-DOOM

When testing the AN-180, use special care to avoid induction hum,
not to mention the general precautions you should observe in test-
ing this type of equipment.

When adjusting a semi-fixed variable resistOrs(particularly of the
10¢ type), be sure to use a screw driver with an insulated handle
(e. g. Part No. 50925740)

After adjustment, secure the semi- -fixed variable resistor with
white paint.

AF oscillator
AC voltmeter Input impedance 100k ohm or more
Frequency response 20 to 20,000 Hz or more

. Attenuator

Distortion. Analyzer

Page 11

PLAYBACK SECTION HARMONIC DISTORTION FACTOR

After making connections as-in the foregoing item a) and perform-
ing calibration as in the foregoing item b), measure the playback
section harmonic distortion factor by means of a harmonic distor-
tion factor meter.
The Specification chart shows the value of distortion factor at
1V output voltage and 1 kHz frequency, 0.5% or less.
PLAYBACK SECTION SIGNAL TO NOISE RATIO

With equipment connected as shown above, measure the playback
section S/N ratio with the LINE OUT terminal shorted.

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