Sansui AM 70 Service Manual

Page 1

SERVICE MANUAL

INTEGRATED STEREO AMPLIFIER

SANS!" 70

(Silver & Black Model)

NOTE
A-M7O is additional model which external appearances
are different from those of .A-M77.

This manUal contains OTHER PARTS LIST, PACKING
LIST and ACCESSORY LIST in which changed parts are
printed with bold-face. . .
For other parts list, refer to A-M77 service manual previ-

ously issued.

SANSUI ELECTRIC CO... LTD.

A-M7O

'SPECIFICATIONS

Power output
Min. RMS, both channels driven, from 40 to 20,000 Hz with
no more than 0.5% total harmonic distortion.
25 watts per channel into 8 ohms.
Load impedance .............. 8 ohms
Total harmonic distortion
.................................. less than 0.5% at or below
rated min. RMS power output

I Frequency response (at 1 watt)

................................... 10 to 50,000 HZ/
+0.5 dB, --2 d8
RIAA curve deviation (PHONO, 30 Hz to 20 kHz)
.................................. +05 dB, ..0_5 dB
Input sensitivity and impedance
(1 kHz, for rated power output)
PHONO ..................... 2.5 mV/47 kilohms
(Max. input capability: 130 mV at 1 kHz, less than
0.5% total harmonic distortion)
TUNER, TAPE-l PLAY
............................. l50 mV/47 kilohms

MIC ........................... 0.5 mV/lO kilohms
Output level (1 kHz)
TAPE REC ................... 130 mV into 47 kilohms
Signal to noise ratio (short-circuit, A-network)
PHONO ..................... 72 dB
TUNER, TAPE-l PLAY
............................. 90 dB

Power requirements
Power voltage ............. 120/220/240 V (50/60 Hz)
For U.S.A. & Canada
........................ 120 V (60 Hz).
Power consumption.... 105 watts 120 VA Rated
150 watts Maximum ,
Dimensions ..................... 345 mm (13-5/8) W
66 mm (2-5/8) H
235 mm (8-11/16) D
Weight ......... . .................. 3.3 kg (7.3 lbs.) net
' 3.8 kg (8.4 lbs.) packed

* Design and specifications subject to change without notice for im.
provements.

Page 2

A-M70

1. OTHER PARTS

0Front View

W
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Parts List
Parts No. Stock No. Description Parts No. Stock No. Description
1 07779920 Knob, MIC, BASS, TREBLE 9 47460000 Knob (L), MASTER VOLUME
2 46556100 20k!) 15A V.R. MIC MIXING (Silver Model)
3 46556000 50k9lC) V.R. BASS TREBLE 47557300 Knob (L), MASTER VOLUME
4 47458000 Front Panel Assy (Silver Model) (Black Model)
47559100 Front Panel Ass'y (Black Model) 10 46555900 150k0 38M x2 VB.
5 47172400 Metal Bonnet (Silver Model) MASTER VOLUME
47558500 Metal Bonnet (Black Model) 11 47460200 Push Knob, POWER
6 47212810 Push Knob, TAPE-2/DA, 12 46364300 Push SW., POWER
LOUDNESS (Silver Model) 13 46556400 Push SW., LOUDNESS
47547100 Push Knob, TAPE-2/DA, 14 46271000 Mini Jack, AUX/HEAD PHONES
LOUDNESS (Black Model) 15 46549400 Jack, PHONES
7 46556300 Push SW., TAPE-2/DA 16 46549300 Jack, MIC
8 47460100 Knob (R), MASTER VOLUME 17 47160000 Side Panel (L)
(Silver Model) 47560000 Side Panel (L)
47557400 Knob (R), MASTER VOLUME 18 47159900 Side Panel (R)
(Black Model) 47560100 Side Panel (R)

2. PACKING LIST

3. ACCESSORY LIST

Parts No. Stock No. Description Stock No. Description
1 07805200 Vinyl Cover 46952500 Operating Instruction
47159800 Styrofoam Packing 46957700 Connection Diagram
3 47592800 Carton Case (Silver Model)
47558300 Carton Case (Black Model)

14-1, lzumi 2-chome, Suginami-ku, Tokyo 168 Japan

PHONE: (03) 324-8891/TELEX: 232-2076 (International Division)

1250 Valley Brook Ave. Lyndhurst, N.J. 07071 USA.

17150 South Margay Ave. Carson, California 90746 USA.

3036 Koapaka Street. Honolulu, Hawaii 96819 USA.

SANSUI ELECTRONICS (U.K.) LTD.: Unit 10A, Lyon Industrial Estate, Rockware Avenue, Geenford, Middx UB6, OAA, England
SANSUI ELECTRONICS G.M.B.H.: Pau Ehrich Strasse 8, 6074 R6dermark 2, West Germany

Printed in Japan (440620M)

SANSUI ELECTRIC CO.. LTD.:
SANSUI ELECTRONICS CORPORATION:

(SM1-169)

Page 5

'STK4I4III (Power Amp. IC)

N

35$ 89l0131

0LC7815H (Analog Function Switch IC)

V V VEE
Outputl 1 A 3 7" Outpulz
Al A2
El 32
Input Input,
Termlnal Termlnal
Cl C1
D1 D2
Wont
Am
3 ,-
Bl" E. 2 K
Control ('1 g
Termlnal g l_n
in '3' =- 7
g; 2 LED
Din .-, E Drive
(E: n E Termmal
RE ET
5
MUTEIn
CR Mule
Control MUTE

Clrcull

A-M77

II!
II
4 I5 I6
0M5218l. (Audio Pre Amp. IC)
U lfl Ill Ill L-"d LI Ill IE
0 - -z l .2 - o +
s 3 $2 5 %3 E s 5
2 g S; " S; g E
i s s 1
_ N
Oulpuk Table of LC7315H
Conditlon of control Connected input Connected
input terminals terminal to termlnal
PonIPln No) output 1 and 2 10 LED
terminals
Aln 5m 0m Dln PORT PORT PORT
(2) (3) (4) (5) (Pin No.) (Pln Noll (Fln Mal
H x >4 )4 A¥(10) A2(19) mm
L H x x Bl(ll) lazuli) atzsl
L L H x mm cum C(25)
L L L H mm) 02(16} 0(24)
H'H level L:L level x Don'l care