McIntosh MC303 AC – 3-Channel Power Amplifier for Main Speakers and Center

The McIntosh MC303 AC is a 3-channel power amplifier with Autoformer technology, designed for high-quality multi-channel applications. It powers the two main speakers as well as the center channel, making it particularly suitable for demanding home cinema setups where the front soundstage, dialogues, and musical reproduction should converge at an appropriately high level.

Autoformer Technology for Flexible Speaker Selection

The MC303 AC is McIntosh's first multi-channel power amplifier with Autoformers. This McIntosh technology ensures that the amplifier delivers its rated output power to various speaker loads. This provides greater freedom in speaker selection without restricting the amplifier to a specific impedance class.

Power Guard and Sentry Monitor for Safe Operation

Power Guard continuously monitors input and output signals and reduces the risk of clipping. This helps to avoid severe sound distortion at high levels. Sentry Monitor complements this protection with a fuse-less short-circuit protection circuit that shuts down the output stage before critical operating values are reached and then automatically resets.

Wattmeters for Direct Control

The three peak-reading wattmeters display program peaks quickly and accurately. This allows for direct reading of the output power of individual channels at all times. For home cinema use, the wattmeters can be switched off if a quieter aesthetic is desired in a darkened room.

High-Quality Craftsmanship in Classic McIntosh Style

The MC303 AC features a thick glass front panel, custom-machined anodized aluminum handles, and a mirror-polished stainless steel chassis.

Pros and Cons at a Glance

Reasons to choose the McIntosh MC303 AC:

• 3-channel power amplifier for front left, front right, and center
• Autoformer technology for flexible speaker selection
• Power Guard to reduce clipping
• Sentry Monitor as a fuse-less short-circuit protection circuit
• Three switchable wattmeters for home cinema applications
• High-quality housing with glass front, aluminum handles and stainless steel chassis
• Large gold-plated five-way binding posts

Things to know about the McIntosh MC303 AC:

• Due to its high weight, stable placement is required

Specifications

General

• Product Type: 3-channel power amplifier with Autoformer
• Dimensions W × H × D: 45.09 × 31.4 × 55.9 cm
• Weight: 70.3 kg net
• Shipping Weight: 81.6 kg
• Frequency Range: 20 Hz to 20,000 Hz as nominal power band

Audio

• Output Power: minimum continuous, average sine wave output power per channel, with all channels in operation: 300 W into a 2-ohm, 4-ohm, or 8-ohm load
• Number of Channels: 3
• Output Load Impedance: 2 Ohms, 4 Ohms or 8 Ohms
• Rated Power Band: 20 Hz ... 20,000 Hz
• Total Harmonic Distortion: maximum 0.005% at a power level ranging from 250 mW to rated power, at 20 Hz ... 20,000 Hz
• Dynamic Headroom: 1.8 dB
• Frequency Response: 0, -0.25 dB / 20 Hz ... 20,000 Hz, +0, -3 dB / 10 Hz ... 100,000 Hz
• Input Sensitivity for Rated Output: 1.7 V unbalanced, 3.4 V balanced
• Signal-to-Noise Ratio, A-weighted: 112 dB below rated output
• Intermodulation Distortion: maximum 0.005%, when the instantaneous peak output power does not exceed twice the rated output power at a combination of frequencies in the range of 20 Hz to 20,000 Hz
• Wideband Damping Factor: > 40
• Input Impedance: 10,000 Ohms
• Output Current: 60 A

Connections

• Speaker Terminals: large gold-plated five-way binding posts
• Inputs: balanced and unbalanced

Features

• Autoformer: present
• Power Guard: present
• Sentry Monitor: present
• Wattmeter: three peak reading wattmeters
• Wattmeter switchable: yes, for home theater applications

Protection Circuits

• Power Guard: total harmonic distortion of less than 2% with a maximum overdrive of 14 dB at 1,000 Hz
• Sentry Monitor: fuseless short-circuit protection circuit with automatic reset

Power Supply

• Power Control Input: 5 V ... 12 V DC
• Power Control Output: 12 V DC, maximum 25 mA, Delay: 0.2 Sec.
• Power Requirement: 240 V, 50/60 Hz at 6 A
• Standby: < 1 W

Material and Housing

• Front Panel: Glass
• Handles: anodized aluminum
• Chassis: mirror-polished stainless steel

Scope of delivery

• McIntosh MC303
• Power cable
• Documents