PAIR OF VINTAGE MCINTOSH MC40 TUBE MONO BLOCK AMP AMPS AMPLIFIER CALIBRATED,
McIntosh power amplifiers were origionally designed for the precision laboratory instrumentation market. Due to their superior sonic attributes they found widespread employment in recording studios driving both cutting lathes and studio monitors. They are equally at home making an audiophile's dream system a reality!
Only McIntosh vacuum tube amplifiers provide this level of performance due to three design innovations. Push-Pull phase inversion is performed with precision at a low signal level by a dedicated stage and then amplified with a true balanced differential amplifier to a voltage level necessary to drive the output stage. The cathode follower driver circuit fully excites output tubes into the positive grid current region (Class AB2) fully utilizing their potential for power output. The proprietary unity coupled output transformer with bifilar primary windings virtually eliminates crossover distortion and extends power bandwidth a full octave above and below that of most designs. The result is simply transparent and realistic sound!
Performance of each amplifier has been varified in a test laboratory to meet or exceed McIntosh specifications. Calibration certificates with data are provided for each amplifier. All of the nine pin tubes are of USA manufacture and have passed stringent testing for leakage and transconductance utilizing a Hickock 6000 laboratory tester. Output tubes are new Sylvania 6L6GC selected for matching idle current and transconductance.
Visual appearance of the pair is stunning! The chrome is bright and shiny over greater than 99% of surface area with minimal pitting. Silk-screen is generally legible (please Supersize Images 10,11, 16 and 17). The original Owner's Manual (in color) is complete with seperate schematic and voltage/resistance trouble-shooting chart.
Prior to shipping, tubes will be removed and identfied as to chasis and socket location. Tubes will be packaged and shipped in a seperate box for safe arrival.