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Overview

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.

McIntosh MC901 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.

McIntosh MC901 Amplifier

Vacuum tubes do not perform at their best when they are amplifying lower frequencies that are not being used by the loudspeaker. With the MC901, the vacuum tube amp will not be burdened with low end reproduction as the solid state section will drive these frequencies. The two amplifier sections of the MC901 are designed to work together in a synergistic relationship and are specifically engineered to assure that each section only amplifies its intended frequencies. Each amplifier section has its own discrete power supply so neither siphons power or performance away from the other. All of this results in easy bi-amping with unparalleled performance and sound reproduction from your speakers.

McIntosh MC901 Amplifier

WATCH: Discover why Steve Guttenberg The Audiophiliac Man "reached new heights of aural ecstasy" when listening to the MC901 Dual Mono Amplifier at the World of McIntosh Townhouse.

Prior to the MC901, bi-amping a speaker required two separate amplifiers. It also required an external crossover, along with a lot of trial and error, to properly configure the two detached amplifiers so they worked together as best as possible. The MC901 solves this issue thanks to its internal, adjustable crossover with the controls easily accessible on the top of the unit. These adjustable crossover filters allow you to optimize the performance of both amplifier sections to your listening preferences. Relative gain levels for each amplifier section can be adjusted from -6dB to +3dB. A direct feed can also be connected to each amplifier section, thus bypassing the filters.

McIntosh MC901 Amplifier

Like virtually all McIntosh amplifiers, the MC901 features an iconic "McIntosh Blue" Watt meter, which has come to be recognized around the world as a symbol of quality home audio. And just like the MC901 itself is a new design, so too is its meter with the introduction of our new DualView™ Power Output Meter. The DualView meter features two of our traditional, fast responding mechanical meters stacked above and below each other in a single meter window; one meter is dedicated to the 300 Watt vacuum tube amp and the other to the 600 Watt solid state amp. Each meter operates independently of the other and displays the real time power reading of each amplifier section.

McIntosh MC901 Amplifier

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

Although the MC901 may look different than any McIntosh product before it, a quick glance reveals signature McIntosh design cues. The top is highlighted by a series of diagrams printed on glass that outline the basic circuitry and specifications of the unit, along with a glass nameplate trimmed with a circular aluminum ring that's finished to match the front panel endcaps. The sides are adorned with vintage McIntosh-styled die cast aluminum name badges. Two classic McIntosh knobs are located on the front of the polished stainless steel chassis, and direct LED backlighting illuminates the DualView meter, McIntosh logo and the lettering on the black glass front panel.

McIntosh MC901 Amplifier with XRT1.1K Loudspeaker

The uncompromising level of fit and finish that is expected of a McIntosh product completes the MC901. It can be combined with a variety of preamplifiers, turntables, CD players, media streamers, speakersand other specialty productsto form a complete home audio system. Contact your local dealerto learn more about this one-of-a-kind home audio amplifier.

Specifications

Electronic Specifications

FTC Power Output Rating

Solid State section: 600 W

Vacuum Tube section: 300 W

Power Output per Channel

Solid State section: 600 W into 2, 4 or 8 ohms

Vacuum Tube section: 300 W into 2, 4 or 8 ohms

Number of Channels

1

Total Harmonic Distortion

Solid State section: 0.005% maximum harmonic distortion at any power level from 250 milliwatts to rated power, 20Hz to 20kHz

Vacuum Tube section: 0.5% maximum harmonic distortion at any power level from 250 milliwatts to rated power, 20Hz to 20kHz

S/N below rated output

Solid State section: 122dB

Vacuum Tube section: 112dB

Dynamic Headroom

Solid State section: 2.5dB

Vacuum Tube section: 1.2dB

Damping Factor

Solid State section: >40

Vacuum Tube section: >18

Rated Power Band

Solid State section: 20Hz to 20kHz

Vacuum Tube section: 20Hz to 20kHz

Frequency Response

Solid State section:

+0, -0.25dB from 20Hz to 20kHz

+0, -3dB from 10Hz to 100kHz

Vacuum Tube section:

+0, -0.5dB from 20Hz to 20kHz

+0, -3dB from 10Hz to 70kHz

Control

Remote Power Control

Yes

Multi-Channel DB25 Cable

N/A

Connectivity

Speaker Binding Post Type

Patented Solid Cinch™ Speaker Binding Posts

General Specifications

Circuit Configuration

Solid State section: Quad Balanced

Vacuum Tube section: Unity Coupled

Circuit Design

Solid State and Vacuum Tube

Mono Bridge

No

Mono Parallel

No

Output Type

Solid State section: Autoformer™

Vacuum Tube section: Unity Coupled Output Transformer

Meters

DualView™ Power Output Meter

Meter Light Switch

Yes

Balanced Input

3 (1 Solid State, 1 Vacuum Tube, 1 Composite)

Front Panel

Glass

Illumination

Direct LED

Chassis Style

Polished stainless steel & black painted steel

Weights & Dimensions

Unit Dimensions (W x H x D)

17-17/32" (44.5cm) x 13-3/8" (34cm) x 29-17/32" (75cm)

Unit Weight

180 lbs (81.6 kg)

Shipping Weight

200 lbs (90.7 kg)

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FAQs

Please read our FAQs page to find out more.

Do you price match?

Yes. We match any authorised dealer, including big-box retailers. If you find the same product at a lower price, contact us and we'll match it.

Do you offer free shipping?

Yes — free shipping on every order, with 2-day delivery available on most products. Easy returns and exchanges are included.

Where is your showroom?

We're at 6362 Alder Drive, Houston, Texas. The showroom lets you hear and compare reference-level systems in person before making any decisions. If you're considering a larger purchase or installation, it's well worth the visit.

Can I buy online without visiting the showroom?

Yes. The full product range is available through the online store with free nationwide shipping. For more complex system builds, speaking with one of our advisers first tends to lead to a better result.

Do you offer financing?

Yes. Special financing is available through the BrandSource Credit Card for qualifying purchases, allowing you to spread payments over time with no annual fee. Promotional rebate savings are also available periodically. See the financing page for full details.

Do you install systems as well as sell equipment?

Yes — installation is central to what we do. We design and install whole-home audio and video, home theaters, media rooms, outdoor audio, lighting and motorised shades, and full smart home automation.

Do you provide support after installation?

Yes. We provide ongoing service and support to ensure systems continue performing as intended — not just on installation day, but over the long term.