McIntosh MC901 Dual Mono Amplifier - Two Amps in One

The McIntosh MC901 is a monoblock amp that drives a single speaker. However, the MC901 is two amplifiers combined into one chassis. Furthermore, you get the best of both worlds in that the MC901 consists of both a 300 Watt vacuum tube amplifier and a 600 Watt solid-state amplifier.

The 300 Watt vacuum tube portion is designed to power your speaker's mid and upper drivers via eight KT88 output tubes, plus four 12AT7 and two 12AX7A signal tubes. That leaves the solid-state section to push its 600 Watts to the power-hungry woofers.

Naturally, the tube amp uses McIntosh's patented Unity Coupled Circuit output transformer 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 all 600 Watts into a 2, 4 or 8 Ohm impedance speaker via the brand's Autoformer technology.

McIntosh MC901 Makes Bi-amping Easy

Usually, bi-amping a speaker requires two separate amplifiers as well as plenty of trial and error (or know-how) along with an external crossover to get two separate amplifiers to sing together. This is where the MC901 hopes to solve the problem. Firstly, thanks to its internal, adjustable crossover with easily accessible controls easily accessible on the top of the unit, you can use the crossover filters to optimise the performance of both amplifier sections. Relative gain levels for each amplifier section is adjustable from -6dB to + 3dB. You can also connect a direct feed that bypasses the filters, should you wish.

Additionally, each amplifier section has its own discrete power supply, so neither siphons power or performance away from the other.

You will no doubt have noticed that the MC901 features McIntosh's DualView Power Output Meter. You get a meter for both sections, one above the other, in the single window showing the power output reading in real-time.

McIntosh Tech

New for the 300 Watt vacuum tube amplifier section is Power Guard Screen Grid Sensor (SGS). 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.

Naturally, everything else is what you would expect from a McIntosh amplifier. The list includes Power Guard in the 600 Watt solid-state amplifier section, Sentry Monitor, Quad Balanced design, Power Control, Solid Cinch speaker binding posts, McIntosh Monogrammed Heatsinks, and McIntosh's eco-friendly Power Management System.

Price and Availability

Orders for the MC901 can be placed now for £39,995 per pair with UK shipping expected to begin in January 2020.

For more information, check out McIntosh.