Pioneer sa 7800 service manual

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MODEL SA-7800 COMES IN FIVE VERSIONS DISTINGUISHED AS FOLLOWS:

Type Voltage Remarks
KU 120V only U.S.A. model

KC 120V only Canada model

8 - 110V, 120V, 220V and 240V (Switchable) General export model

SIG 110V, 120V, 220V and 240V (Switchable) US. Military model

HG 220V and 240V (Switchable) Europe or Oceania model

0 Although the basic features of KU, KC, 8, S/G and HG types are the same. The major differ-
ence is in appearance, KU, KC and 8/6 types being fitted with wooden case, while 8 and HG
types employ metal cover.

0 This service manual is applicable to the KU type. When repairing the KC, S and 8/6 types,
please see the additional service manual (ART-354-0). When repairing the HG type, please see
the additional service manual (ART-3450).

CONTENTS
1. SPECIFICATIONS ..................... 3 9.10 Phone Jack Assembly (GWX-260) ....... 31
2. FRONT PANEL FACILITIES .............. 4 9.11 Indicator Assembly (AWV-001) ......... 32
3. BLOCK DIAGRAM ..................... 6 9.12 Switch Assembly 2 (GWS-170) ......... 33
4. CIRCUIT DESCRIPTIONS 9.13 Power Supply Assembly (GWR-112) ...... 34
4.1 Phono Circuit ..................... 6 10. PACKING ........................... 35
4.2 Tone Controls .................... 7
4.3 Power Amplifier ................... 7
4.4 Indicator Circuit ................... 9
4.5 Protection Circuit .................. 10
5. ADJUSTMENTS ....................... 11
6. DISASSEMBLY ....................... 12
7. PARTS LOCATION .................... 13
8. EXPLODED VIEW ..................... 15
9. SCHEMATIC DIAGRAMS. P.C. BOARD
PATTERNS AND PARTS LIST
9.1 Miscellanea ...................... 18
9.2 Schematic Diagram ................. 19
9.3 P.C. Board Connection Diagram ......... 23
9.4 Equalizer Assembly (GWF-l 15) ......... 27
9.5 Tone Amplifier Assembly (GWG-123) ..... 28
9.6 Terminal Assembly (GWX-259) ......... 29
9.7 Volume Assembly (GWX-258) .......... 29
9.8 Switch Assembly 1 (GWS-169) ......... 29
9.9 Power Amplifier Assembly (GWH-118) . . . . 30