MC2.1KW Monoblocks 75th Anniversary

The McIntosh MC2.1KW 75th Anniversary is a tri-chassis power amplifier delivering 2,000 Watts. It is designed for home stereo and home theatre systems, and can be used with McIntosh loudspeakers or a wide range of other speakers. The amplifier is suited to power-hungry loudspeakers and systems installed in very large rooms.

The MC2.1KW is available separately, or as part of the McIntosh Reference Music System and Reference Home Theatre System. It pairs with the XRT2.1K Loudspeaker and its predecessor, the XRT2K.

For the 75th Anniversary in 2024, the first 75 pairs of MC2.1KW sold in each country where McIntosh is distributed include special anniversary badging.

The amplifier comprises 3 separate modules, consisting of 1 Output Module and 2 Power Modules. Each Power Module contains a 1,000 Watt amplifier. The incoming audio signal enters the Output Module from the preamplifier, where an in-phase signal is sent to 1 Power Module and an out-of-phase signal to the other. After amplification, both signals return to the Output Module and drive opposite ends of the bi-filar wound McIntosh Autoformer™. The signals are then combined into 1 output, with the power summed and noise reduced or cancelled. A low-distortion signal leaves the Output Module for the loudspeaker.

The 3-module construction also addresses practical installation and handling requirements. Each module weighs over 120 lbs (54 kg), whereas a single module containing the complete amplifier would weigh close to 400 lbs (181 kg). Separating the amplifier into 3 modules makes each one more manageable to move. It also allows each module to use a common household plug. A single-module design would require a high-voltage outlet, such as the type used by electric ranges in the United States, and special wiring inside the walls.

McIntosh's hand-wound Autoformer delivers the full 2,000 Watts into loudspeakers with 2, 4 or 8 Ohm impedance. The amplifier therefore does not reduce its power output when the speaker impedance differs from the amplifier's output impedance. Amplifiers with only 1 output impedance can lose up to half of their available power when connected to a loudspeaker with a different impedance.

The MC2.1KW follows the MC2KW, which was introduced at the 2005 CES Show. Its upgrades include substantially larger filter capacitors, improving low-frequency performance and dynamic headroom. The 8 larger capacitors are installed in the Power Modules behind the custom Power Bank visible through the front panel glass.

Each Power Module has 4 McIntosh Monogrammed Heatsinks™. Constructed from materials with high thermal conductivity and connected to advanced high-current output transistors, they dissipate heat while eliminating thermal equilibrium lag time. Other updates include enhanced circuit designs with modern components and shorter signal paths, updated electrical wiring, bayonet IP68-rated interconnect cables between the 3 modules, and direct LED front-panel lighting.

McIntosh patented Solid Cinch™ speaker binding posts attach speaker cables securely and help prevent them from loosening and causing a short circuit. The posts are gold-plated to resist corrosion and maintain the signal connection. Separate binding posts are provided for 2, 4 and 8 Ohm impedances, with each impedance rating placed on its own output platform at the rear of the Output Module. Each output platform has 3 sets of identical binding posts for bi-wiring or tri-wiring a loudspeaker.

Dual sets of balanced and unbalanced inputs allow more than 1 preamplifier to be connected. They can be used to switch between vacuum tube and solid state signals, including the 2 output types provided by the C12000 Solid State and Vacuum Tube Preamplifier, or between separate vacuum tube and solid state preamplifiers. The second input set can also connect 2 preamplifiers of the same type. This allows the preferred signal type to be selected for different music and listening preferences.

The MC2.1KW includes the following McIntosh technologies:

• Power Guard®, which monitors the incoming audio signal and makes real-time adjustments if the amplifier is at risk of being overdriven. These adjustments prevent harsh clipping that could damage loudspeakers and are designed to be inaudible.
• Sentry Monitor™, a fuse-less short-circuit protection circuit that disengages the output stage before current exceeds safe operating levels and resets automatically when normal conditions return.
• Quad Balanced design, which cancels virtually all noise and distortion that may have entered the audio signal.
• Power Control, which sends power on and off signals to connected McIntosh components, including CD players, turntables, tuners and media streamers, for system start-up and shutdown.

The MC2.1KW has polished stainless steel casework, black glass front panels, illuminated logos, rotary knobs, aluminium handles and a blue Watt meter.