This comprehensive service manual provides detailed technical information and repair instructions for the Marantz SR66 and SR66U audio receivers. It includes schematics, block diagrams, parts lists, troubleshooting guides, adjustment procedures, and other essential information for technicians and service personnel. The manual covers all aspects of the receivers' operation and repair, from basic troubleshooting to advanced component level repair. With its detailed diagrams and clear instructions, this service manual empowers technicians to diagnose and repair malfunctions efficiently and effectively.

The Marantz SR66 and SR66U are stereo receivers manufactured by Marantz, a renowned Japanese electronics company known for its high-quality audio equipment. These receivers were released in the late 1970s and were popular choices for audiophiles seeking a balance of performance and affordability. The SR66 and SR66U share a similar design and feature set, with the SR66U offering a few additional functionalities. Both receivers are capable of handling a wide range of audio sources and deliver a clear, detailed sound. Both the SR66 and SR66U are equipped with a robust amplifier section capable of delivering a respectable amount of power. The amplifier is designed to provide a clean and accurate sound reproduction, with minimal distortion even at high volumes. The receivers also feature a sensitive tuner section, capable of picking up weak radio signals with clarity. They offer a range of input options for connecting various audio sources, including a phono input for turntables, a tape input for cassette decks, and multiple auxiliary inputs for connecting other devices. These inputs allow users to enjoy a variety of audio sources with ease. Moreover, they are equipped with a speaker selector switch, enabling you to choose between different speaker configurations, allowing for flexibility and versatility in system setups. The SR66U adds an additional feature – a built-in Dolby B noise reduction system, which enhances the listening experience by reducing noise and improving sound quality, particularly for recordings made on cassette tapes.