Sansui D 970 Service Manual

Page 1

D-970

SERVICE MANUAL

Track . .' ........ 4-Track (2-Channel Stereo)
Tape speed ....... 4.8 cm/sec, (1-7/8 ips)
Heads .......... Record/Playback: Ferrite
STEREO 3-HEAD CASSETTE DECK
Erase: Double Gap Ferrite Head
' Motor .......... Capstan: FG Servo Motor
Reels: DC Motor
- Wow and flutter , . . . within 0.025 % WRMS
snnsul n 970 Fast wind time ..... approximately 80 seconds
(C-60)

Frequency response (Record/Playback)
Normal Tape (LH) (-20 VU)
............ 20 to 19,000 Hz
(30 to 18,000 Hz :3 (18)
Metal Tape (-20 VU)
............ 20 to 23,000 Hz
(30 to 22,000 Hz :3 dB)
(0 VU) . 30 to 13,000 Hz 13 dB
Signal to noise ratio (Record/Playback)
Metal Tape (without Dolby Noise Reduction Effect)
............ better than 61 dB (weighted)
(With Dolby Noise Reduction)
B-NR ...... . better than 71 dB (above 5 kHz)
CvNR ...... . better than Bl dB (above 1 kHz)
Erasure factor (Metal Tape)
............ more than 65 dB at 1,000 Hz
input sensitivity and impedance (0 VU, 1,000 Hz)
MIC ......... 0.4 "IV/2005'! ~ 5 kn
LINE EN (REC) . . 70 mV/47 kn
Output level (0 VU, 1,000 Hz)
LINE OUT (PLAY) 350 mV

PHONES ...... 200 mV
Power requirements
Power voltage . . . . 100,120,220, 240 V (50/60 Hz)
For USA. and Canada
........... 120 v (60 Hz) »
Power consumption
............ 40 W
Dimensions ....... 430 mm (16-15/16) W

111 mm (4-3/8") H

324 mm (12-3/4") D
Weight .......... 7.1 kg (15.7 lbs) net

8.2 kg (18.1 lbs) packed

Design and specifications subject to changes without
notice for improvements.

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

Sang-Lu:
SANSUI ELECTRIC CO., LTD.

Page 2

D 970

1.

BLOCK DIAGRAM

PLAY LINE

P B NEAD

LINE IN C

hICI DOLBV NR

:-

lNDlCATOR AMP LEVEL MEYER

Hay Ilval ADJ
lVRz momma Pa LT'°5'
9" U D U u
sounc:
OUY PUT LEVEL
g {b E pnouzs
IVR I
0 LINE our
FLAT 2. a, MC: Dom NR
A M P
.4
SIGNAL R E C EEC wMPU-TREC REC
SELECTOR LEBE} mp SWITCHIMS AMP
3
Ivan
k X 0 l
BIAS
+3 ems use -|
kVR I

2. OPERATION OF COMPU-TREC

(COMPUterized-Tape REsponse Control)

Fig. 2-1 olC3b comparator input terminal level

LEVELlV)

oIC3b Pin Noll

T2

Time (Sec)

0 Since the mechanism operations and electrical operations em-
ployed in D-970 are similar to those of D-570, back tension servo
operation is similar to that of D-SSOM, the explanations of these
operations are omitted from this manual.

Fig. 2-2

Output level at mosI

suitable bias PEAK
METAL -2dB
- HIGH a.
NORMAL} 4

REC/PB OUTPUY LEVEL

I I
I I
l l
: I
| I
I l
I l
I !

Most suflable bIaS
BIAS Cuvrant (,A)