This original service manual is a must-have for any BOSE 101/121 Music Monitor System enthusiast. It contains detailed information on how to properly maintain and repair your vintage audio equipment. With step-by-step instructions and diagrams, you can easily troubleshoot and fix any issues that may arise. The manual covers all aspects of the system, from schematics and wiring diagrams to assembly and disassembly instructions. Whether you're a collector or a musician, this manual will provide valuable insight into the inner workings of the BOSE 101/121 Music Monitor System.