User manual MCINTOSH MC2250 BROCHURE

[. . . ] It not only provides the output transistors an ideal load and is the path that conducts any DC away from the loudspeaker, it 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. In stereo, the Mclntosh autotransformer perfectly matches the output circuit to 1, 2, 4 or 8 ohms. In mono, (Mclntosh stereo amplifiers can be interconnected for mono and deliver twice the power) the autotransformers provide matching ½, 1, 2, 4, 8 or 16 ohms. [. . . ] patent #4048573). MC 2155/MC 2255 USE McINTOSH POWER METERS The lack of accurate performance in ordinary meters has presented difficult and complex problems. Ordinary meters are incapable of indicating the short interval information in a sound wave. Short interval information can have a duration of onehalf 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. Mclntosh engineering solved both problems by developing new electronic circuits the meters will respond to 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, peak-locking meter circuit is a patented Mclntosh design (U. S. A variety of information can be displayed on the meters, power in watts, to lock and hold only the highest power indications, or three different peakreading peak-locking decibel indications. THE McINTOSH AUTOMATIC TEST SYSTEM The Mclntosh Automatic Test System provides performance protection and extends the long troublefree life of an amplifier. Each time the amplifier is turned on, the Automatic Test System electronically measures and verifies accurate performance at seven critical points in the amplifier's circuits. The Automatic Test System verification assures operational readiness before operation starts and limits any damage should there be component malfunction. You are informed when each test is verified by an LED number indicator. THE McINTOSH "ALWAYS IN STYLE" The appearance of a Mclntosh 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 panels are selected to be free from bubbles, flow marks and other faults. It is reverse silk screened with thermal setting epoxy screen inks which practically become a part of the glass. Knobs, meticuously machined of solid aluminum then anodized and thermally and electrically isolated, compliment the overall appearance. Anodizing is an electro-chemical process that leaves a color dyed and hardened surface that is impervious to attack from common household cleaning fluids, oils and acids from the skin and is highly wear resistant. The aluminum "Pro-Panel" on the MC 2150 and MC 2250 is a combination of anodized gold and attractive baked enamel. Its versatility permits ease of custom installation, installation in the Mclntosh furniture cabinet or can be easily converted to professional rack mounting with accessory adapters. The deletion of the meters and their associated controls and circuits are the only electrical differences between these high performance models. This handsome combination of glass, anodized aluminum and epoxy requires very little maintenance to keep that, "Just new" appearance. The subtle yet sophisticated styling is designed to complement any decorative scheme and will remain in "good taste". ince 1949, Mclntosh has continuously expanded the boundaries of power amplifier technology and performance with the introduction of each new design. [. . . ] We promise you that when you purchase a new Mclntosh from a Mclntosh 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. Mclntosh protects your listening and your investment. Protection 5. To assure you of the Mclntosh belief in design for long life, Mclntosh goes beyond the ordinary guarantee. You are offered a Mclntosh 3 Year Service Contract which protects you from the cost of repair for three full years. [. . . ]