User manual MCINTOSH MC240

[. . . ] As little as one degree (centigrade) rise in temperature can reduce the operating life of the amplifier 10%. McIntosh has extended the life of its amplifiers by engineering for cool operation. McIntosh cool operation requires a combination of careful design of the output circuit, containing the output circuit in a mechanical housing that permits the use of generous sized heat sinks to provide great heat dissipation capability along with chassis construction Cooling air, flowing through the air tunnel, easily dissipates any life limiting heat generated. THE MCINTOSH (EXCLUSIVE) POWER GUARD MUSIC PROTECTION CIRCUIT Improved recordings and recording techniques have imposed higher power demands on today's amplifiers. Poorly designed amplifiers, of which there are many, can present music listeners with a form of harsh unpleasant distortion due to amplifier overload {hard clipping). [. . . ] The mass of the meter movement is too great to respond to the nearly instantaneous changes in music program material. That short interval information can have a duration as short as one-half of one thousandth of a second. Even if the meter were capable of such high velocity movement, the human eye could not perceive the information. By developing new electronic circuits the meters are made to respond to short intervals with an accuracy of 98%!To permit the eye to see such high speed motion, the electronic circuits that drive the meter pointer are time stretched so the meter pointer position can register in the persistence of vision characteristics of the human eye. The peak-reading, peaklocking meter circuit is a patented McIntosh design (U. S. You may elect to observe the delivered power in watts demanded by the musical program or you may elect to lock and hold only the highest power indications yet have continuous updating as higher powers are delivered or you may select from three different peak-reading, peak-locking decibel indications. Each selected function is indicated by illuminated nomenclature on the panel. THE MCINTOSH "ALWAYS IN STYLE" The appearance of a McIntosh speaks eloquently of precision, quality, premier performance and long, trouble-free life. Consider the construction and materials used in the front panel and knobs. Each constituent part is selected for long, wear-resistant life and stable attractive styling. The panel of the MC 2155 is select glass, free from bubbles, flow marks and other faults. With the McIntosh autotransformer, matching the output circuits to the loudspeakers, any direct current component is shunted to ground. Your speakers are protected completely from this kind of amplifier failure. We promise you that when you purchase a new McIntosh from a McIntosh franchised dealer, it will be capable of or can be made capable of performance at or exceeding its published performance limits or you can return the instrument and get your money back. To assure you of the McIntosh belief in design for long life, McIntosh goes beyond the ordinary guarantee. You are offered a McIntosh 3 Year Service Contract which protects you from the cost of repair for three full years. Should your McIntosh instrument fail, McIntosh will provide the service materials and labor needed to return the measured performance at the original performance limits. The SERVICE CONTRACT does not cover any shipping costs to and from the authorized service agency or the factory. McIntosh protects your investment. ADAPTABILITY accessory adapters. their associated controls ectrical differences between these two MC 2150 with optional RMAS VERSATILE MCINTOSH POWER AMPLIFIERS DELIVER FULL POWER - ALWAYS The McIntosh auto transformer is a silent giant in insuring better performance and protection. First, it is the ideal method of coupling the output circuit to the loudspeakers which are the load into which the output of the amplifier is fed. Frequently the loudspeaker can compromise amplifier performance by speaker impedance variations with frequency or by multiple speakers connected to the amplifier. [. . . ] Should there be any direct current component in the output circuit, the autotransformer conducts any speaker damaging DC directly to ground. Your expensive loudspeakers are protected from this potentially damaging circumstance. A third benefit of the McIntosh autotransformer, which not only provides the output transistors an ideal load and is the path that conducts any DC away from the loudspeaker, also contributes a flexibility in loudspeaker connecting capability not otherwise possible. For safe operation ordinary amplifier output circuits are usually restricted to operate into 4 or 8 ohms. [. . . ]