MC901 Dual Mono Amplifier – First Look

All Image Credit: McIntosh

Now this is my type of power amplifier, see here for my original stereo system. It echoes everything that I used to do and own and its the best of both worlds; valve for its gentle and detailed mids and highs and solid-state for its tight and clean bottom end control. Plus it has an adjustable crossover built in to ensure that each power amplifier only receives its optimal frequency range. Its not cheap though at almost $17,500 for EACH channel!!

This MC901 mono block amplifier has to be the best amplifier on the market for those of you who can bi-amp their speakers and afford the luxury to do so. The MC901 has been designed for bi-amping speakers. It’s two amplifiers in one; a 300W valve amplifier and a 600W solid-state amplifier on one chassis. The valve section would be used to drive the loudspeaker’s mid and upper drive units using eight KT88 output valves, four 12AT7 and two 12AX7A signal valves, and the solid-state section delivers its 600W directly to the bass drivers. WOW! Each amplifier has its own dedicated power supplies, can drive 2, 4 and 8 ohm using McIntosh’s unique transformer technologies providing identical performance, and with the adjustable crossover controls can be optimized to suit the amplifier and your speaker arrangement.

McIntosh has been designing vacuum tube amplifiers since the 1940’s and solid state amplifiers since the 1960’s. The MC901 is probably the ultimate solution to bi-amping embodying all those years of design development and know how.

Each MC901 is a mono block amplifier that drives a single speaker, it contains two power amplifiers and a crossover that can be adjusted so that each amplifier only handles those frequencies that the drivers it supports handle. Thus optimizing the performance of each power amplifier. Frequency and gains may be adjusted to suit both the speakers frequency response and your own personnel listening preferences. If required the filters may be bypassed by using the amplifiers direct input. Prior to this optimized and combined arrangement, as in my case, you needed a combination of stereo and mono block amplifiers and an external electronic crossover.

This new design also offers plenty of protection for both the amplifier(s) and speakers. It provides Power Guard® in the 600 Watt solid state amplifier section and  Sentry Monitor™, plus a brand new technology in the 300 Watt vacuum tube amplifier section, Power Guard Screen Grid Sensor™ (SGS). Power Guard SGS™ helps prevent premature vacuum tube failure by monitoring the screen grid current in the KT88 output vacuum tubes. If the current becomes too high, a circuit in Power Guard SGS is activated which then dynamically attenuates the input signal in real time to keep the vacuum tubes operating at safe levels.

With its one of a kind stylish design, metering, badging, exceptional and uncompromising level of build and design quality it could only be a McIntosh.

See the McIntosh website for more detailed technical information.

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