Pioneer a 70 service manual

Page 1

(U) PIONEER

Sefiice

ORDER NO.
ARP- 345-0

STEREO AMPLIFIER

A-7O

MODEL A-70 COMES IN SEVEN VERSIONS DISTINGUISHED AS FOLLOWS:

Typo Volt-go Ramuk:

KU AC 120V only U.S.A. model

KC AC 120V only Canada model

HE AC 220V, 240 (switchable) Europaan continent mwel _
HB AC 220V. Z40V (switchable) United Kingdom model

S AC 110V, 120V, 220V, 240V (switchable) General expori model

SIG AC IIOV, 120V, 220V, 240V (switchable) U.S. Military model

HEZ AC 220V, 240V (swichablel West Germany model

o This service manual is applicable to the KU type. For servicing of the other types, please refer to the
additional service manual.

0 Ce manual d'insiruction se refére au mode de réglage, en franCais.

0 Esta manual de de servicio tram del método de ajuste escrito en espafiol.

CONTENTS

1. SPECIFICATIONS .................... 2 6. RC. BOARDS CONNECTION DIAGRAM 17
2. FRONT PANEL FACILITIES ............ 3 9. SCHEMATIC DIAGRAM ............... 21
3. PARTS LOCATION ................... 5 10. ELECTRICAL PARTS LIST ............. 25
4. BLOCK DIAGRAM ................... 7 11. SAFETY INSTRUCTIONS .............. 29
s. CIRCUIT DESCRIPTIONS .............. s 12. ADJUSTMENTS ..................... 30
6. PACKING .......................... 1o REGLAGE ......................... 31
7. EXPLODED VIEWS AND PARTS LIST ...... 11 AJUSTE ........................... 32

PIONEER ELECTRONIC CORPORATION 44, Magma rename. Meguro-ku. Tokyc 153. Japan
PIONIIH ELECTRONICS [UIA] Inc. 1925 E. DornI'I'Iguez SD, Long Beach. Califorms 90910 LLSJX.

PIONEEH ELECTRONIC [anions] N.V. Keecbergla-n 1. 2740 Beveren. Belglum

PIONEEH :Lsc'rnomca Aua'rnAuA p'rv. LTD. 178-184 Boundary Road, Braeslde. chcona 3195. Ausmaha

YX © APR. 1983 Printed in Japan

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A-7O

1. SPECIFICATIONS

Amplifier Section

Continuous Average Power Output is 120 watts
per channel, min, at 8 ohms from 20 Hertz to
20,000 Hertz with no more than 0.003 %
total harmonic distortion?

Continuous Power Output at (Hz
(both channel driven)
T. H, D_ 0.03%, 8 ohms ........ 130watts per channel
T.H.D. 0.1%, 8 ohms. . . . 140 watts per channel (DIN)
Total Harmonic Distortion (20 Hertz to 20,000 Hertz, 8
ohms)
continuous rated power output
..................... No more than 0.003%
60 watts per channel power output
..................... HNo more than 0.003%
lntermodulation Distortion (50 Hertz: 7,000 Hertz = 4:1,
8 ohms)
continuous rated power output

...................... No more than 0.003%
Damping Factor (20 Hertz to 20,000 Hertz, 8 ohms)
................................... 60
Input (Sensitivity/Impedance)
PHONO MM ................ 2.5mV/50 kilohms
PHONO MC ................. 200pV/100 ohms

TUNER, CD/AUX, TAPE PLAY 1, 2
........................ 150 mV/50 kilohms
Phono Overload Level (T.H.D. 0.005%, 1,000Hz)

PHONO MM ........................ 150mV

PHONO MC ......................... 11mV
Output (Level/Impedance)

TAPE REC 1, 2 ............. 150mV/2.2kilohms

Frequency Response
PHONO (RIAA Equalization)
................... 20Hz to 20,000Hz t0.2dB
TUNER, CD/AUX, TAPE PLAY 1, 2
..................... 5H2 to 100,000Hz:gdB
Tone Control

BASS ....................... t10dB(100Hz)

TREBLE ..................... i10dB (10kHz)
Filmr

LOW (SUBSONIC) ............ 15Hz (-6dB/oct.)

Loudness Contour (Volume control set at -40dB)
................... +6dB (IOOHZ), +3dB (10kHz)
Hum and Noise (IHF, short circuited A network)

PHONO MM ........................ 37.53

PHONO MC ......................... 70dB

TUNER, CD/AUX, TAPE PLAY 1, 2 ........ 108dB
Rum and Noise (DlN, continuous power/50mW)

PHONO MM .................... BOdB/SSdB

PHONO MC ..................... 70dB/65dB

TUNER, CD/AUX, TAPE PLAY 1, 2 . . . . 95dB/69dB
Muting .............................. -20dB

Miscellaneous

Power Requirements
........................... AC120V, 50/60Hz
Power Consumption ..................... 450W
Dimensions .......... 420(W) X 131 (H) x 41 1 (D) mrn
16-9/16lW) x 5-3/16(H) x 16-3/16lD) in
Weight (without package) ......... 12.3kg (27 lb 2 oz)

Furnished Paris
Operating Instructions ....................... I

Measured pursuant to the Federal Trade Commissions Trade
Regulation rule on Power Output Claims for Amplifier.

" Measured by Shibasaku 725 Automatic Distortion Analyzer.

N 0 TE:
Specifications and design: suhiect to possible modifica tion without
notice.