WhitakerAudio J C Whitaker 20 W Stereo Audio Amplifier, Manual

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Table of Contents
1 Circuit Description 8
1.1 20 W Stereo Amplifier Module 8
1.1.1Amplifier Circuit 8
1.1.2Power Supply 12
1.1.3Preamplifier Power Supply Module 13
1.2 Power Management Module 15
1.2.1Power Management Expansion Board 19
1.3 General Considerations 21
2 Parts List 24
3 PWB Design 34
3.1 20 W Stereo Amplifier Module 34
3.1.1Amplifier PWB #1 (right) 35
3.1.2Rectifier PWB 38
3.1.3Amplifier PWB #2 (left) 40
3.1.4Speaker Terminal PWBs 43
3.2 Preamplifier Power Supply Module 45
3.3 Power Management Module 47
3.3.1Power Management Expansion Board 49
4 Construction Techniques 52
5 Step-by-Step Instructions 54
5.1 Assembly of the 20 W Stereo Amplifier PWB #1 (Right Channel) 55
5.2 Assembly of the 20 W Stereo Amplifier PWB #2 (Left Channel) 65
5.3 Assembly of the Preamplifier Power Supply Module 74
5.4 Assembly of the Power Management Module 78
5.5 Assembly of the Power Management Expansion Board 83
5.6 Chassis and Final Assembly 87
5.6.1Front Panel Components 87
5.6.2Back Panel Components 90
5.6.2.1 Back Panel Auxiliary Power Connector 92
5.6.3Cable Clamps and Related Hardware 94
5.6.4Install Printed Wiring Boards 97
5.6.5Install Transformers 98
5.6.6Install Remaining Chassis Components 100
5.6.7Wire the Transformer Leads 100
5.6.7.1 Cable Organization 100
5.6.7.2 Right Channel Output Transformer Primary Leads 103
5.6.7.3 Left Channel Output Transformer Primary Leads 103
5.6.7.4 Power Transformer Leads 104
5.6.7.5 Choke Leads 106
5.6.8PWB Interconnections 107
5.6.9Primary Power Connections 110
5.6.10Chassis-Mounted Control 114
5.6.11 Headphone/Speaker Connections 115