MC275 MK VI

The McIntosh MC275 MK VI is a vacuum tube power amplifier for high-end two-channel audio systems. It provides 75 watts per channel in stereo or 150 watts in mono, using KT88 output tubes and McIntosh Unity Coupled Circuit output transformer technology.

The amplifier can be used in stereo with 4, 8 or 16 ohm loudspeakers, delivering 75 watts per channel. In mono operation, it produces 150 watts into 2, 4 or 8 ohms. McIntosh's patented Unity Coupled Circuit output transformers allow the full rated power to be delivered across these supported speaker impedances.

Now in its sixth generation, the McIntosh MC275 incorporates a series of refinements while retaining the design approach of the original amplifier. Its wide-bandwidth output transformers support control, bass power and a smooth presentation, combining the character associated with vacuum tube amplification with the ability to drive a wide range of high-performance loudspeakers.

The output stage uses 4 KT88 vacuum tubes. The input, voltage and driver stages are supported by 4 12AT7 tubes and 3 12AX7A tubes. This valve arrangement gives the MC275 its scale, dynamics and vacuum tube character.

Connectivity includes balanced XLR and unbalanced RCA inputs for use with a range of preamplifiers and audio systems. Gold-plated McIntosh Solid Cinch speaker binding posts provide the speaker connections, while Power Control connections allow compatible McIntosh components to switch on and off together.

McIntosh Sentry Monitor protection continuously checks operating conditions and can disengage the output stage if current exceeds safe levels. The amplifier restores normal operation automatically when conditions return to normal.

The smaller vacuum tubes have LED illumination to show operating status. They glow amber during start-up and change to green when the amplifier is ready for use. If an output tube develops a fault, its corresponding indicator changes to red to identify the affected tube.

First introduced in 1961, the MC275 was originally produced until 1971, when solid-state amplification became more widespread. McIntosh returned the model to production in 1993, and the MC275 has remained part of the range for more than 6 decades. Its combination of McIntosh styling, vacuum tube engineering and 75 watts per channel makes it suitable for both contemporary and traditional two-channel systems.