McIntosh MC255 – 5-Channel Power Amplifier for High-Quality Home Theater

The McIntosh MC255 is designed as a 5-channel home theater power amplifier for systems where multiple speakers need to be controlled and operated reliably. It is suitable for 5-channel home theater setups but can also be used in a two-zone configuration.

TripleView Display with Switchable Illumination

The wide TripleView™ Power Output Meter display shows the power of the three front channels separately in real-time. The typical McIntosh illumination provides a striking look, but it can be switched off so it doesn't distract from the TV or projection image during movie night.

Protection through Power Guard® and Sentry Monitor™

Power Guard® protects against clipping and amplifier overdrive, which can stress speakers. Sentry Monitor™ protects the output stage in case of short circuits and automatically resets once safe operating conditions are restored.

Quiet Cooling with Heatsinks™

Four McIntosh Monogrammed Heatsinks™ cool the amplifier efficiently and silently. This eliminates the need for distracting fans that could interfere with the movie sound in the room. A specially wound toroidal isolation transformer also supports the quietest possible operation.

Connections and Operation

Balanced and unbalanced inputs are available for connection to a home theater processor. Speakers are connected via gold-plated binding posts. On the front, there are classic McIntosh rotary controls for power and meter illumination; in addition, the MC255 supports Power Control for automatic power on and off via compatible McIntosh components.

Setup and Room Planning

Due to its high weight of over 40 kg, careful consideration should be given in advance to where the McIntosh MC255 will be positioned. The rack or furniture used must be sufficiently stable and designed for this load. In addition, sufficient space should be planned for safe placement and ventilation.

Design with Classic McIntosh Signature

The black glass front, illuminated logo, aluminum end caps, tactile rotary controls, and TripleView display continue the familiar McIntosh design.

Pros and Cons at a Glance

Reasons to choose the McIntosh MC255:

• 5-channel power amplifier for home theater systems
• TripleView™ Power Output Meter with switchable illumination
• Power Guard® and Sentry Monitor™ protection circuits
• Balanced and unbalanced inputs
• Fanless cooling via McIntosh Monogrammed Heatsinks™

Important considerations for the McIntosh MC255:

• Mono Bridge and Mono Parallel are not supported
• Due to its size, weight, and heat generation, careful placement planning is important.

Specifications

General

• Product Type: 5-Channel Home Theater Power Amplifier
• Type: Solid State
• Circuit Configuration: Push-Pull Complementary
• Circuit Design: Solid State
• Number of Channels: 5
• Two-Zone Operation: 3 channels in Zone A and 2 channels in Zone B possible
• Dimensions W × H × D: 44.5 × 23.9 × 53.3 cm
• Weight: 40.6 kg
• Shipping Weight: 55.6 kg
• Frequency Spectrum: 20 Hz to 20 kHz

Audio

• FTC Power Output Rating: 250 W
• Power per Channel when using the three front channels: 250 W into 4 or 8 Ohms
• Power per Channel when using all five channels: 200 W into 4 or 8 Ohms
• Output Load Impedance: 4 Ohms and 8 Ohms
• Total Harmonic Distortion: 0.005 %
• Signal-to-Noise Ratio: 108 dB below rated power
• Dynamic Headroom: 3.6 dB
• Damping Factor: >70 into 4 Ohms, >140 into 8 Ohms
• Frequency Response: +0, -0.25 dB from 20 Hz to 20 kHz
• Extended Frequency Response: +0, -3 dB from 10 Hz to 100 kHz
• Input Sensitivity: 2.2 V balanced with 4-ohm speaker; 1.1 V unbalanced with 4-ohm speaker; 3.0 V balanced with 8-ohm speaker; 1.6 V unbalanced with 8-ohm speaker
• Input Impedance: 20,000 Ohms balanced, 10,000 Ohms unbalanced
• Voltage Gain: 29 dB
• Intermodulation Distortion: 0.005 % maximum
• Power Guard: less than 2% THD with up to 14 dB overdrive at 1,000 Hz

Connections

• Balanced Inputs: 5
• Unbalanced Inputs: 5
• Speaker Connections: gold-plated standard binding posts
• Speaker Binding Post Type: Standard
• Power Control Inputs ZA and ZB: 5–15 VDC, less than 1 mA
• Power Control Outputs ZA and ZB: 12 VDC, 50 mA maximum total
• Power Control Output Delay: 0.2 seconds from power-on
• Multi-Channel DB25 Cable: no

Features and Controls

• TripleView™ Power Output Meter
• Meter Light Switch: yes
• Remote Power Control: yes, 5-channel or 3 + 2 channel
• Power Guard®: present
• Sentry Monitor™: present
• Dynamic Power Manager®: present
• McIntosh Monogrammed Heatsinks™: present
• Front Panel: Glass
• Illumination: Direct LED
• Chassis Style: Inverted
• Mono Bridge: no
• Mono Parallel: no
• Auto-Off / Power Save: Standby after approximately 30 minutes without audio input signal
• Load Switch: 4-Ohm or 8-Ohm setting

Power Supply

• Mains Voltage: factory configured, field conversion not possible
• Available Versions: 100 V, 50/60 Hz, 12.0 A; 110 V, 50/60 Hz, 11.0 A; 120 V, 50/60 Hz, 10.0 A; 127 V, 50/60 Hz, 10.0 A; 220 V, 50/60 Hz, 6.0 A; 230 V, 50/60 Hz, 6.0 A; 240 V, 50/60 Hz, 6.0 A
• Standby Consumption: less than 0.5 W

Setup and Installation

• Installation: freestanding on four feet or custom installation in furniture/cabinet
• Minimum Clearance for Ventilation: 15.24 cm top, 5.08 cm bottom, 7.62 cm rear, 5.08 cm per side
• Clearance in front of Mounting Panel: 2.22 cm
• Cutout for Installation: 43.18 × 37.30 cm
• Ventilation Opening in Mounting Base: 40.64 × 26.7 cm

Shipping Dimensions and Weight

• Shipping Carton W × H × D: 74.9 × 43.2 × 73.7 cm
• Shipping Weight: 55.6 kg

Scope of Delivery

• McIntosh MC255
• Power Cable
• Documents
  

• Datenblatt
• Anleitung
• Broschüre