McIntosh MR77 FM Tuner - SOLD

Even since the beginning of FM, research engineers have realized that constant delay, or linear phase, IF filters were necessary for low distortion reception. Crude approximations to constant delay have always been used in FM tuners — with disappointing results. So-Called "Butterworth" or "Legandre" filters offer only a fair compromise with respect to delay error. Crystal and ceramic filters, usually based on the "Chebychev" model, work fairly well and give good selectivity, but none of these are constant delay (linear-phase) filters. Commercial tuners using these filters can show 5% stereo IM distortion at 100% modulation, and have delay errors up to 100%. In sharp contrast, the linear phase filter allows a tuner to show only .1% IM distortion at 100% modulation and has a delay error of only 1.2% in the useful bandpass. In its useful bandpass, it is a true mathematical approximation to linear-phase — the world's finest selective, linear-phase, minimum-phase shift filter.

A FORTRAN computer program using an algorithm that took six years to develop was used in its design. The mathematical complexity of the filter design procedure is almost beyond belief. Using a process called "numerical integration in the complex S-plane," a high speed IBM 1130 computer spent eighteen minutes on the design of the MR 77 IF filter. A human engineer, working twenty-four hours a day and seven days a week, would have taken 300 years to finish this work . . . assuming he made no mistakesl" - McIntosh Sales Media 1970

Sounds sooo complicated but this is the way McIntosh wrote about their products. Always over the top in their descriptions and in the way they spoke about new and exciting technology that was becoming mainstream, (IBM 1130 computer, lol). Anyway this Mac FM Tuner is absolutely PRISTINE. ZERO blemishes or flaws of any kind. Just a 100% all original piece from one of the most respected names in the audio industry. Could rattle off all the specs but honestly, the most important thing here is that it pulls in stations with the utmost clarity and its presentation is pure McIntosh. You will not find a cleaner piece. Comes complete with original box, OM and all packaging.

Come listen to this fine Mcintosh FM Tunet at our Lawrence shop or buy with confidence via this website.