Pioneer sr 303 service manual

Page 2

MODEL SR-303 COMES IN THREE VERSIONS DISTINGUISHED AS FOLLOWS:

Tvpe Voltage Remarks
KU 120V only U,S.A. model

S 110V, 120V) 220V and 240V (Switchable) General export model

S/G 110V, 120V, 220V and 240V (Switchable) U.S. Military model

Although the basic features of KU, S and 8/6 types are the same, the variations in safety
standards in different countries has also necessitated variations in power supply and circuit

component specifications.

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

to the additional service manual (see page 19).

CONTENTS

I. SPECIFICATIONS ..................... 2
2. FRONT PANEL FACILITIES .............. 3
3. REAR PANEL FACILITIES ............... 4
4. BLOCK DIAGRAM ..................... 4
5. CIRCUIT DESCRIPTIONS ................ 5
6. DISASSEMBLY ....................... 8
7. PARTS LOCATION .................... 9
8. ADJUSTMENT ........................ 10
9. EXPLODED VIEW ..................... 10
10. SCHEMATIC DIAGRAM, P.C. BOARD
PATTERNS AND PARTS LIST
10.1 Miscellanea ...................... 12
10.2 Schematic Diagram ................. 13
10.3 P.C. Boards Connection Diagram ........ 15
10.4 Parts List of P.C. Board Assemblies ....... 17
11. PACKING ........................... 18

1. SPECIFICATIONS

Semiconductors

ICs ................................... 8
FET ................................... 1
Transisitors ............................. 20
Diodes ................................ I6

Reverberation Amplifier Section
Input (Sensitivity/Impedance) .......... 150mV/50kfl
(at lkHz, DEPTH volume: 0)
Frequency Response ............ 5H2 to 70kHz tldB
(at DEPTH volume: 0)
Total Harmonic Distortion .......... Less than 0.05%
(at lkHz, 1V, DEPTH volume: 0)
Maximum Input Level ...................... 2V
(at lkHz, 1V, DEPTH volume: 0)
Signal to Noise Ratio ..................... 90dB

(at IV, DEPTH volume: 0)
Reverberation Time . . . 0 to 3 sec (at EFFECT 1, 400Hz)
25msec to lOOmsec (at EFFECT 2, 400Hz)
Output (Level/Impedance) ............ lSOmV/I kg
(at 1kHz, DEPTH volume: 0)

Miscellaneous

Power Requirements ......... llOV/IZOV/220V/240V
(switchable), 50/60Hz
Power Consumption ...................... 13W
Dimensions ........... 420(W) x 99(H) x 336(D) mm
16-9/I6(W) x 3-7/8(H) X I3-1/4(D) in
Weight (without package) ........... 4,3kg (9 lb 8 oz)
Furnished Parts
Connection cord with pin plugs ................. 2
Operating instructions ....................... 1
NOTE:

Specifications and the design subject to possible modifica-
tion without notice due to improvements.