Sansui D 770R Service Manual

Page 1

SERVICE MANUAL

Track .......... 4-Track (2»Cnannel Stereo)
Tape speed , . , . . , A 4.8 cm/scc. (1-7/8 ipsl
Heads . .. ....... Record/Playback: High Bs Hard

AUTO REVERSE CASSETTE DECK Parm'wv

Erna: Double Gap Ferrite Head

Motor .......... Capstan: Electronically Controlled
DC Motor
A "I .77 Reels: DC Moror
Methanism: DC Moxor
Wow and flutter , . . . within 0.04% WRMS
Fast wind time . , . . approximately 80 seconds (060)

Frequency response (Record/Playback)
Normal Tape (Ll-l) ( -»2O VU)
............ 20 to I7,000 H2
(3510 16,000 HZ :3 (33)
Metal Tape (-20 VU)
............ 20 to 20,000 HZ
(35(018,000 Hz :3 dB)

i
l ? (0 VU) . 35 1013,1100 H2 13 :18
'F Signal to noise ratio {Record/Playback)
l ij L :2 Metal Tape (without Dolby Noise Reduction Errm)
l - - -- -.-_:| - ............ beuer than 60 dB (weighted)
i 0 L. U U D (With Dolby Noise Reduction)
8-NR . 4 . . V . . . . better than 70 dB (aboves kHz)
C-NR ......... better than 80 dB (above I kHz)
Erasure lactor [Metal Tape)
............ more than 70 dB 3:1,000 Hz
Input sensitivity and impedance (0 VU, 1,000 HZ]
MIC ......... 0'4 HIV/2009 ~ 5 kn
LINE IN (REC) t. , 70 mV/47 kfl

Output level (0 VU, 1,000 H1)
LINE OUT (PLAY)

350mV
PHONES ...... IOO mV
Power requirements
Power vollage t . t i00,120, 210, 240 V (50/60 Hz)

For USA. and Canada
........... 120 v (60 Hz)
Power consumption 32 W
Dimensions ....... 430 mmiléAIS/lé) W
H] mml4-3/8")H
324 mm (l2«3/4") D
Weight ,,,,,,,,,, 66 kg (I45 lbs) net
7.7 kg (17,0 lbs) packed

Design and specifications subject to changes without
noxice for improvemznls»

' Noise reduction system manufactured under license from
Dolby Laboratories Licensing Corporation.
Dolby" and the double D symbol are trade marks of
Dolby Laboratories Licensing Corporation.

SANSUI ELECTRIC 00., LTD.

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1. BLOCK DIAGRAM

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2. OPERATIONS

2-] . Features can be made, even if the operation starts from either of the
forward direction or the reverse direction.

Memory play, memory stop, two-point memory repeat functions

by microcomputer control.

Successive double~face (A and B surfaces) record/play operation,

15-music jump music-selection, and AMPS functions.

Electronic dual-mode counter function of taperun time period

display and four-digit counter display.

6) Two motors for driving the capstan and the reel, and one sepa-

rate cam motor for engaging/disengaging the pinch roller.

Dolby B-type and C-type NR systems.

This Model No. D-770R is a stereophonic cassette deck provided 3)

with two microcomputers and a Dolby C system, by which forward-

and-reverse recording/playing quickly-reversing function has been
newly realized.

I) Quick-turn reverse function 5)
An independent microcomputer is mounted for controlling
automatic reverse operation, and an infrared ray photocoupler is
used to detect the magnetic tape end. Therefore, the tape feedA
ing direction can momentarily be switched from forward direc-
tion ( D ) to reverse direction ( 4 ) and the fixed-type four-track
head can also momentarily be switched from forward record/ 2_2_ Mechanism Operation
play line to reverse record/play line.

2) Three tape-feeding modes by reverse mode selector A. Driving 0f 6253513" 3""! take-up reels (5 Fix. 21)

Z :One-way record/play operation can be made in either of the Fig. 2,] Driving of capstan and take~up reels
forward direction or the reverse direction.

DzBoth-way record/play operation can be made beginning from
the forward direction. Beginning from the reverse direction, WWW! Tekamoflom
one way record/play operation can be made.

Q: In the case of recording operation, after the both-way record- .
ing operation beginning from the forward direction has been 10le IE
completed, automatic endless playing operation is successive-
ly made in such a way as from A surface, through B surface,
to A surface - - - -. After the one~way recording operation
beginning from the reverse direction has been completed,
automatic endless playing operation is successively made in
such a way as from A surface, through B surface, to A surface

in the case of playing operation, endless playing operation

4

7

FR Idler Noel Motor

Censun Mata!

Capella Shem

c-psun Stu-«(RI