McIntosh MC901 1-Channel Dual Mono Amplifier

• Includes our Hybrid Drive^™ technology that uses the best of vacuum tubes and solid state to produce the best sound performance
• The ultimate solution for bi-amping loudspeakers: 300 Watt vacuum tube amplifier and 600 Watt solid state amplifier on one chassis
• Vacuum tube section powers mid and upper drivers
• Solid state section drives power hungry woofers
• DualView™ Power Output Meter

McIntosh has been perfecting vacuum tube amplifiers since the 1940s and solid state amplifiers since the 1960s. Our amplifiers have been used at many historic events including presidential inaugurations and Woodstock, as well as in landmark sound systems like the Grateful Dead's Wall of Sound and Despacio. From that heritage comes a truly one-of-a-kind home audio amplifier only we could dream of, design and build as the ultimate solution for bi-amping loudspeakers: the McIntosh MC901 Dual Mono Amplifier.

The MC901 is a monoblock amplifier that drives a single speaker. But it is unlike any other monoblock amplifier. What makes the MC901 so unique is that it's two amplifiers combined into one. Adding to the uniqueness is that each amplifier is of differing design philosophies: the MC901 consists of a 300 Watt vacuum tube amplifier attached to a 600 Watt solid state amplifier on one unified chassis.

The MC901 includes our Hybrid Drive^™ technology that uses the best of vacuum tubes and solid state to produce the best sound performance. The 300 Watt vacuum tube portion powers the speaker's mid and upper drivers via eight KT88 output tubes, plus four 12AT7 and two 12AX7A signal tubes; the solid state section delivers 600 Watts of dedicated power to the power hungry woofers. The 300 Watt vacuum tube amp in the MC901 uses our patented Unity Coupled Circuit output transformer – the same technology McIntosh was founded on in 1949 – to deliver its full 300 Watts into almost any speaker regardless if it has 2, 4 or 8 Ohm impedance. Similarly, the 600 Watt solid state amp delivers its full 600 Watts into a 2, 4 or 8 Ohm impedance speaker via our Autoformer™ technology.

While an entirely new design, the MC901 comes with the technology one would expect from a McIntosh amplifier:

• Power Guard^® that monitors and adjusts the input signal in the 600 Watt solid state amplifier section in real time, then makes unobtrusive adjustments to prevent harsh sounding distortion and potential speaker damaging clipping.
• Power Guard Screen Grid Sensor™ (SGS). The 300 Watt vacuum tube amplifier section of the MC901 breaks new ground as it's our first amplifier to feature our new Power Guard SGS™ technology. Power Guard SGS helps prevent premature vacuum tube failure by monitoring the screen grid current in the KT88 output vacuum tubes. If the current becomes too high, a circuit in Power Guard SGS is activated which then dynamically attenuates the input signal in real time to keep the vacuum tubes operating at safe levels.
• Sentry Monitor™ observes the output current and shuts the amplifier off if it ever exceeds safe limits.
• Quad Balanced design that cancels virtually all noise and distortion that may have crept into the audio signal.
• Power Control that can send power on/off signals to other connected McIntosh components for easy system power up and shutdown.
• Our patented, gold-plated Solid Cinch™ speaker binding posts that easily and securely attach the speaker cables.
• McIntosh Monogrammed Heatsinks™ that are connected to advanced high current output transistors efficiently cool the solid state amplifier section.
• Our Power Management System that will turn the entire unit off after a set amount of time when no input signal has been detected.

Specifications