McIntosh’s Autoformer multichannel amplifiers, side by side. Here is the 5-channel MC255 alongside the 7-channel MC257 and 3-channel MC303 and their specifications, showing what your money buys.

The MC255 is McIntosh’s 5-channel Autoformer power amplifier, and the amplifier for a home cinema that wants the full McIntosh treatment across the main speakers without stretching to seven channels. It brings the technologies that define McIntosh’s stereo amplifiers, the Autoformer output and the blue meters, to home theatre, in a single chassis that drives a 5.1 system or the main five channels of a larger one. It is a power amplifier, so it needs an AV processor in front of it and speakers to drive.

Brief product overview

A 5-channel solid-state power amplifier rated at 250 watts per channel, and, because of McIntosh’s Autoformer output stage, the full 250 watts is delivered into 2, 4 or 8 ohms alike, so the amplifier is largely indifferent to speaker impedance. Power Guard prevents audible clipping and Sentry Monitor protects the output stage on every channel. There are balanced and unbalanced inputs, Solid Cinch binding posts, and a TripleView power output meter that displays the output of multiple channels at once. The chassis carries the black glass front panel with the illuminated logo, and it is built in Binghamton, New York, where they have been building them since 1949.

How it sounds

The MC255 brings McIntosh’s composed, slightly warm, unforced character to a cinema, with the Autoformer output giving it a grip on demanding speakers that a conventional multichannel amplifier lacks, and the headroom to stay unstrained through the loudest passages. Its 250 watts a channel drive the front and surround speakers of a home theatre with real authority, so film soundtracks have scale and impact and multichannel music has body. As a power amplifier it takes its sound from the processor and speakers it partners, but it brings the McIntosh quality and power that lift a cinema above a receiver-based system.

What we’d partner it with

The MC255 needs an AV processor and speakers. It pairs with McIntosh’s AV processors, the MX200, MX123A or the flagship MX180, which handle the decoding, video and room correction, with the MC255 driving five channels; for layouts beyond five channels, a further amplifier drives the additional speakers. For speakers, a timbre-matched package from Sonus faber, Focal, Monitor Audio, KEF or Fyne Audio, with subwoofers from REL, SVS or KEF, builds a complete system.

On cabling, use appropriate speaker cable for the runs; AudioQuest and Chord are the cable brands we stock.

Who shouldn’t buy it

If your system needs seven channels of the same Autoformer power, the MC257 is the amplifier to choose. If you want reference power on the critical front three channels specifically, the 3-channel MC303 pairs with a separate surround amplifier. And if you would rather not run a separate amplifier at all, the MHT300 receiver builds seven channels of amplification into one box.

Setup notes: The MC255 is a large, heavy amplifier and wants ventilation above and around it. Connect each speaker to the Autoformer tap that matches its impedance, 2, 4 or 8 ohms, rather than to whichever posts are nearest, since that is where the load-tolerance comes from. Run the processor to the amplifier on balanced cables where you can. The meter and logo can be dimmed or turned off.

Warranty & service: McIntosh components carry a warranty when bought from an authorised dealer; service is handled through the UK distributor.