Service Manual
This section contains the entire Chroma Service Manual complete with large format Schematics and Drawings in PDF format. This is the final 1983 version (as opposed to the 1982 version with ARP schematics). System Overview discusses the overall architecture of the Chroma. Circuit Descriptions contains detailed information on all of the main boards. Disassembly includes diagrams for removal of the cover panel and power supply. Calibration and Checkout and Parts List are self-explanatory. Mnemonics is a reference for abbreviations used throughout the manual.
Thanks to Martin Straw [21010093+] for providing a copy, and David Clarke [21030085++] for reviewing these pages and providing graphics of equations in Circuit Descriptions.
Contents
Section 1: System Overview
- General Description
- Dual Channel Architecture
- System Interfacing
- System Block Diagram
- System Structure
Section 2: Circuit Descriptions
- Computer Board
- I/O Board
- Dual Channel Board
- Channel Mother Board
- Power Supply
- EQ Board
- Stack Switch Boards
Section 3: Disassembly
Section 4: Diagnostics
Section 5: Calibration and Checkout
- Power Supply Ripple
- Preregulator D.C. Voltage
- +5V Analog DC Voltage
- DAC Output Null Trim
- The "Scratch Patch"
- Oscillator Trim Procedure
- Alternate Trim Procedure
- Channel Assignment
- Tuning Check
- Swapping Channel Boards
- Alternate Tuning Check
- Damper Bar Adjustment
- Stack Switch Adjustment
Section 6: Schematics and Drawings
- Computer Board Assembly
- Computer Board Schematic
- I/O Board Assembly
- I/O Board Schematic 1
- I/O Board Schematic 2
- Channel Mother Board Assembly
- Channel Mother Board Schematic
- Dual Channel Board Schematic 1
- Dual Channel Board Schematic 2
- Left Stack Switch Assembly and Schematic
- Right Stack Switch Assembly and Schematic
- EQ Board Schematic and Assembly
- Power Supply Assembly
- Power Supply Schematic
- Interconnection Diagram 1
- Interconnection Diagram 2
- Balanced Output Schematic and External Interface Cable Schematic
Section 7: Parts List
- Computer Board
- I/O Board
- Channel Mother Board
- Dual Channel Board
- Left Stack Switch Assembly
- Right Stack Switch Assembly
- EQ Board
- Power Supply