Pioneer A-450R Service Manual

Y PIONEER’
The Art of Entertainment
Service
ORDER NO.
ARP2305
STERO AMPLIFIER
A-550R
A-550R-S
A-450R
A—550R, A—550R-—S AND A-—450R HAVE THE FOLLOWING :
Model
* Change the connection of the power transformer’s primary wiring.
Power Requirement
* This manual is applicable to the A — 550R/HE, HEWZ, A — 550R — S/HEWZ, A — 450R/HE and HEWZ
types.
* The A—550R-—S is the same as the A— 550R except for color.
¢ Ce manuel pour le service comprend les explications de réglage en francais.
e Este manual de servicio trata del método ajuste escrito en espanol.
CONTENTS
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2. SCHEMATIC DIAGRAM cececccccecrceeteteeeeeee teens 7 BASIS TE 2 seesiieeettegesshdatiesyaaain: buccal a eetyes 30
3. P.C.BOARDS CONNECTION DIAGRAM ------ 12 6. PANEL FACILITIES -----1e-seetrretrttrrtrtrretteee 31
4. PCB’s PARTS LIST -cccecccceerceeteceete tee ete teees 21 7. SPECIFICATIONS -ccccccccc creer ete e teen cere teen eens 33
PIONEER ELECTRONIC CORPORATION = 4-1, Meguro 1-Chome, Meguro-ku, Tokyo 153, Japan
PIONEER ELECTRONICS SERVICE INC. P.O. Box 1760, Long Beach, California 90801 U.S.A.
PIONEER ELECTRONICS OF CANADA, INC. 505 Cochrane Drive, Markham, Ontario L8R 8E3 Canada
PIONEER ELECTRONIC [EUROPE] N.V. Keetberglaan 1, 9120 Beveren, Belgium
PIONEER ELECTRONICS AUSTRALIA PTY. LTD. 178-184 Boundary Road, Braeside, Victoria 3195, Australia TEL: [03] 580-9911
© PIONEER ELECTRONIC CORPORATION 1991 DX JULY 1991 Printed in Taban’

Pioneer A-450R Specifications

General

Frequency Response	5 Hz to 100 kHz
Input Sensitivity (Line)	150 mV
Input Sensitivity (MM)	2.5mV
Signal to noise ratio (MM)	80 dB
Total Harmonic Distortion (THD)	0.05% (20Hz - 20kHz, 8 ohms)
Speaker Load Impedance	6 ohms to 16 ohms
Dimensions	420 x 125 x 350 mm
Power output per channel	60 W (8 ohms)

Summary

Exploded Views and Parts Lists

A-550R/S Model Parts List

Detailed parts list for A-550R and A-550R-S amplifier models.

A-450R Model Parts List

Detailed parts list for the A-450R amplifier model.

Packing Information

Information regarding the packing of the unit.

Exterior Views

Visual representation of the unit's exterior components and layout.

Circuit Schematics

AF Complex Assembly Circuit Diagram

Circuit diagram for the Audio Frequency complex assembly.

Tone and Headphone Circuit Diagrams

Circuit diagrams for Tone and Headphone assemblies.

Control, Power Supply, and Fuse Schematics

Circuit diagrams for Control, Power Supply, and Fuse assemblies.

LED and Rotary Function Circuit Diagrams

Circuit diagrams for LED and Rotary Function assemblies.

PCB Wiring Diagrams

PCB Component Lists

Power Switch and Control PCB Parts

Parts list for Power Switch, Control, LED, and Relay assemblies.

Transformer, Capacitor, Resistor PCB Parts

Parts list for Transformer, Capacitor, Resistor, and miscellaneous components.

Adjustment Procedures

Idle Current Adjustment

Steps to adjust the idle current for optimal performance.

Front Panel Controls and Features

Front Panel Control Overview

Explanation of front panel switches, indicators, and controls.

Input Selectors and Tone Controls

Details on Phono, Speaker selectors, and Bass/Treble tone controls.

Special Function Buttons (Subsonic, Loudness, Direct)

Explanations for Subsonic filter, Loudness, Direct, and Muting functions.

Product Specifications

Amplifier Performance Specs

Detailed technical specifications for amplifier output and distortion.

Input Sensitivity and Frequency Response Specs

Specifications for input sensitivity, impedance, and frequency response.

Power, Dimensions, and Accessories

Information on power supply, consumption, dimensions, and weight.