The McIntosh MR66 is a vintage AM/FM tuner that features a striking front panel made from anodized gold and black aluminum. It boasts a user-friendly design with separate AM and FM tuning controls, an illuminated dial, and signal strength and tuning meters. The AM function switch allows users to choose between multiplex FM, AM output, and various bandwidth options including narrow, medium 1, medium 2, and broad. The mode selector switch provides options for mono AM, mono FM, stereo, or power off, enhancing versatility in listening preferences. The AFC (automatic frequency control) can be adjusted from minimum to maximum to optimize tuning. The rear panel includes multiplex output, FM multiplex adapter power connection, and provisions for external antennas with screw terminals. It also has an AM antenna switch to toggle between an antenna or loop, and a lamps switch for adjusting brightness. The fuse and unswitched AC outlet add to its practicality. In terms of specifications, the FM section has a sensitivity of 3.25 uV, a response range of 20Hz-20kHz with ± 2dB variation, and a distortion level of less than 0.8%. The capture ratio stands at 1 to 0.7, and the AM section features a sensitivity of 1.5 uV with several selectivity bandwidth options. A whistle filter provides 70 dB rejection at 10 kHz with an audio output of 4 volts. The MR66 is powered by a combination of various tubes, including (2) 6BN4A, 12AT7, and multiple others, contributing to its warm sound character. Produced between June 1960 and 1961, only 1,353 units were made, with serial numbers ranging from 1N001 to 2N347 and 100G1 to 118G1. It serves as a stereo simulcast AM/FM tuner and requires an outboard MA-6 multiplex adapter for FM stereo functionality, providing a robust solution for radio enthusiasts of its time.
