Technical Description
McIntosh Laboratory, the company who introduced the world’s first amplifier that could be called “High Fidelity”, has done it again. The McIntosh engineering staff has cre- ated a power amplifier without compromise, using the most advanced McIntosh circuit design concepts.
A continuous average power output rating of 200 watts and with an output current of greater than 50 amperes per channel, making this the most advanced Integrated Ampli- fier McIntosh has ever manufactured. The distortion limits for the MA6900 are no more than 0.005% at rated power output for all frequencies from 20Hz to 20,000Hz. Typical performance at mid frequencies is less than 0.002%. The true distortion readings on the MA6900 are so low, it takes special measuring techniques to make accurate readings. The MA6900 can deliver the best possible performance from any type of high quality loudspeaker system.
Creating an amplifier with this level of performance did not come easily. Many months of design, testing and mea- suring were required. Extensive controlled listening tests, the ultimate form of measuring, were made before the final design was accepted.
Preamplifier Design Philosophy
All signal switching in the MA6900 is done by Electro- Magnetic devices.
technology that uses the latest in materials and manufactur- | ||
ing methods. Each switch consists of a glass tube that is | ||
filled with an inert oxygen- |
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free atmosphere and sealed |
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with tiny leads protruding |
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from either end. These leads |
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extend into the tube and |
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overlap one another with a |
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separation of a few thou- |
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sandths of an inch. The leads |
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are made from a ferrous ma- |
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terial that is influenced by a |
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magnetic field. They are first | dB | |
plated with gold as a base | ||
(Decibel) | ||
material, then with rhodium | ||
and finally ruthenium. Ru- thenium is the best contact material known.
The glass assembly is then placed in the center of a multilayer coil of copper wire. The entire assembly is molded together in a tough shock absorbing material.
Figure 10
Bottom Inside View of the MA6900
The switch and coil connectors extend from the bottom in the form of printed circuit board terminals. When a DC voltage is applied to the coil, current flows and creates a
Hz (Hertz)
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