McIntosh MC901 1-Channel Dual Mono Amplifier

Description

The McIntosh MC901 Dual Mono Hybrid Amplifier is one of the most ambitious and technically accomplished amplifiers ever created for the home. Drawing on decades of McIntosh expertise in both valve and solid state amplification, the MC901 delivers a definitive solution for bi-amping high-performance loudspeakers, combining power, refinement and control in a single, integrated design.

Each MC901 is a monoblock amplifier, purpose-built to drive a single loudspeaker. What sets it apart is its dual-amplifier architecture, integrating a 300-watt vacuum tube amplifier and a 600-watt solid state amplifier on one unified chassis. Using McIntosh Hybrid Drive™ technology, the MC901 assigns each amplifier section to the frequencies it handles best, allowing the system to perform at a level unattainable with conventional designs.

The 300-watt valve amplifier powers the midrange and high-frequency drivers, preserving harmonic richness, texture and spatial realism. It uses eight KT88 output tubes, supported by 12AT7 and 12AX7A signal tubes, and McIntosh’s patented Unity Coupled Circuit output transformer, delivering full power into 2, 4 or 8 ohm speakers. Low frequencies are handled by the 600-watt solid state amplifier, which uses Autoformer™ technology to provide consistent output into any common speaker impedance with absolute authority and control.

By removing low-frequency demands from the valve amplifier, the MC901 allows the tubes to operate in their optimal range, improving efficiency, reducing stress and enhancing musical performance. Each amplifier section has its own dedicated power supply, ensuring neither section compromises the performance of the other. The result is seamless, effortless bi-amplification with exceptional scale and coherence.

Unlike traditional bi-amping systems that require multiple amplifiers and external crossovers, the MC901 features an internal adjustable crossover, with controls conveniently located on the top panel. Crossover points and relative gain can be finely adjusted to match loudspeaker design and personal preference, while direct inputs allow the internal crossover to be bypassed entirely when required.

Performance feedback is provided by the striking DualView™ Power Output Meter, featuring two independent mechanical meters stacked within a single window. One meter displays output from the valve amplifier, the other from the solid state amplifier, offering real-time insight into the MC901’s unique dual-amplifier operation.

Comprehensive protection and control technologies are built in throughout. Power Guard® protects the solid state amplifier from clipping, while Power Guard Screen Grid Sensor™ (SGS) safeguards the KT88 output tubes by monitoring screen grid current and dynamically adjusting signal levels if required. Sentry Monitor™ provides fuse-less short-circuit protection, and the Quad Balanced design cancels noise and distortion before it reaches the output stage. Power Control, Solid Cinch™ speaker binding posts, Monogrammed Heatsinks™, and an intelligent power management system complete the design.

Visually, the MC901 is unmistakably McIntosh yet entirely unique. Glass-printed circuit diagrams adorn the top panel, while the black glass front panel, illuminated logo, DualView meter, polished stainless steel chassis and aluminium detailing reflect the brand’s uncompromising approach to build quality and finish.

At Hidden Home Technology, we specify the McIntosh MC901 for clients seeking the ultimate amplification solution for bi-ampable loudspeakers. Correct speaker matching, crossover setup and installation are critical to unlocking its full performance potential within reference-level two-channel systems.

Click here to see the more compact hybrid option – McIntosh MC451 Dual Mono Hybrid Amplifier

Click here for the McIntosh website – McIntosh MC901 Dual Mono Hybrid Amplifier