McIntosh MC255 - Black glass

Description

The McIntosh 5-Channel Home Theater Power Amplifier

The MC255 is McIntosh's 5-channel power amplifier built specifically to drive the main, center, and surround speakers of a home theater installation. Classic black glass front panel with the TripleView™ blue-illuminated meter, McIntosh aluminum control knobs, illuminated logo, and aluminum end caps — the McIntosh look at home in the living room. The MC255 is a direct successor to the previous McIntosh 5-channel amplifier and addresses the improvements that home theater listeners were waiting for.

250 W x 3 Front Channels or 200 W x 5 Channels Through Dynamic Power Manager®

Through McIntosh Dynamic Power Manager® (DPM) technology, the MC255 delivers 250 W per channel when only the three front channels (left, center, right) are used, or 200 W per channel when all five channels run simultaneously. Regardless of how many channels are used, full rated power is available into 4 or 8 ohm loads. Rated total harmonic distortion 0.005%, 108 dB signal-to-noise below rated output, damping factor greater than 140 into 8 ohm loads (greater than 70 into 4 ohm loads). Frequency response +0/-0.25 dB from 20 Hz to 20 kHz (+0/-3 dB from 10 Hz to 100 kHz).

Key Upgrade: Filter Capacity +50%, Dynamic Headroom Doubled

Compared to the previous McIntosh 5-channel amplifier, the MC255's filter capacity is increased by 50%, which more than doubled dynamic headroom — from 1.7 dB to 3.6 dB. A critical improvement for a home theater amplifier: the most violent transients in a film soundtrack (explosion, gunshot, impact) demand an instantaneous power reserve the amplifier can draw on without distortion. Low-frequency performance was also improved by the larger capacitors. On the three front channels, power was increased by 25% — from 200 W to 250 W per channel — for more dynamic dialogue and a stronger front stage.

New 15 in. Wide TripleView™ Power Output Meter

The MC255's TripleView™ meter is a complete redesign of the front-channel display: instead of three separate windows as on the previous McIntosh 5-channel amplifier, the TripleView™ houses three independent mechanical needle meters in a single 15 in. (38 cm) wide glass window. The three needles display real-time instantaneous power for the left, center, and right channels — easy to read at a glance during a movie. The signature McIntosh blue illumination (and the trademark that goes with it) can be turned off via the dedicated front-panel button so it doesn't compete with the TV or projection screen during a movie. Direct LED front-panel lighting for improved color accuracy and durability.

Two-Zone Mode: Three Channels in One Zone, Two in Another

The MC255 can be operated as a 2-zone amplifier: the three front channels at 250 W in zone A (for example the main home theater room), and the two surround channels at 200 W in zone B (for example an adjacent room, or a stereo listening spot elsewhere in the home). A useful configuration for homeowners who want centralized amplification serving two separate zones while keeping the McIntosh signature in both.

Dolby Atmos®, DTS:X™ and Auro-3D® Expansion with MI128 or MI254

For installations that need more than 5 amplified channels — for example Dolby Atmos®, DTS:X™, or Auro-3D® configurations with additional ceiling or surround speakers — McIntosh recommends pairing the MC255 with the MI128 (8 channels) or MI254 (4 channels) digital amplifiers. The MC255 then handles the most demanding main channels while the additional height or surround channels are covered by the auxiliary digital amplifier. A coherent full Atmos or 3D solution, all McIntosh.

Silent Cooling, Toroidal Transformer, and Eco Auto Power-Off

The MC255 runs cool and quiet thanks to four McIntosh Monogrammed Heatsinks™ coupled to high-current output transistors for passive thermal dissipation — no noisy cooling fans that would interfere with the movie soundtrack. A specially wound quiet toroidal isolation power transformer further reduces electrical noise floor. Eco-friendly auto power-off: the amplifier turns off after a programmable interval if no input signal is detected, saving energy without manual intervention.

Power Guard®, Sentry Monitor™, and Standard Gold-Plated Speaker Posts

The MC255 carries the McIntosh proprietary protection circuits. Power Guard® monitors the input signal continuously and dynamically adjusts gain at near-speed-of-light response to prevent hard clipping of the output stage — critical for tweeter protection and for preserving signal quality at high listening levels, and imperceptible to the listener. Sentry Monitor™ is a fuse-less short-circuit protection circuit that disengages the output stage before current exceeds safe operating levels, then automatically resets once conditions return to normal. Standard McIntosh gold-plated speaker binding posts accept bare wire, banana plugs, or spade lugs, and resist corrosion. 5 balanced XLR and 5 unbalanced RCA inputs on the rear panel for connection to a home theater processor.

Common Questions

How much power does the MC255 actually deliver?

Two modes: 250 W per channel when only the three front channels (left, center, right) are used — useful in a stereo-augmented home theater or in a system where surround channels are handled by another amplifier — or 200 W per channel when all five MC255 channels run simultaneously. In either case, full rated power is available into 4 or 8 ohm loads through Dynamic Power Manager® technology. The unit's FTC rated output is 250 W.

What's the difference between the MC255 and the MC257?

The MC255 is the 5-channel amplifier (250 W × 3 front channels or 200 W × 5 channels) and the MC257 is the 7-channel amplifier that delivers the same tri-mode power (250 W × 3 front channels or 200 W × 7 channels). Choose the MC255 for a native 5.1 installation or a system where additional Atmos channels are amplified separately (for instance with an MI128 or MI254). Choose the MC257 to amplify 7 channels in a single McIntosh chassis.

Can I add Atmos or DTS:X channels to the MC255?

Yes, McIntosh explicitly recommends pairing the MC255 with the MI254 (4-channel) or MI128 (8-channel) digital amplifiers to add the additional surround, back, or height channels needed for object-based Dolby Atmos®, DTS:X™, or Auro-3D® formats. The MC255 then powers the most demanding main channels while the additional channels are handled by the auxiliary digital amplifier, in a fully McIntosh chain.

Which McIntosh home theater processor pairs best with the MC255?

McIntosh recommends the MX124 A/V processor or the MX200 A/V processor as natural partners for the MC255 in a full home theater system. The MC255's balanced XLR and unbalanced RCA inputs (5 of each) accept either without compromise. Round out the system with the MPC1500 power controller and McIntosh loudspeakers such as the XR100 (floor standing), LCR80 (LCR), WS500 or WS300 (in-wall), and CS200 (in-ceiling) for a fully coherent McIntosh setup.

What's in the Box

McIntosh MC255 5-Channel Power Amplifier

AC power cord

Power Control cable (3.5 mm)

Owner's manual