Monoblock Amplifier

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Only available for in-store purchase.

Product Description

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 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.

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.

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.

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.

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.

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. 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 preamplifiersturntablesCD playersmedia streamers and other specialty products to form a complete home audio system. Contact your local dealer to learn more about this one-of-a-kind home audio amplifier.

  • Power Output per Channel
    Solid State section: 600 Watts @ 2, 4 or 8 Ohms
    Vacuum Tube section: 300 Watts @ 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 20,000Hz

    Vacuum Tube section: 0.5% maximum harmonic distortion at any power level from 250 milliwatts to rated power, 20Hz to 20,000Hz

  • 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 20,000Hz
    +0, -3dB from 10Hz to 100,000Hz

    Vacuum Tube section:
    +0, -0.5dB from 20Hz to 20,000Hz
    +0, -3dB from 10Hz to 70,000Hz

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)

Brand

McIntosh

Viewed as the standard bearer by recording artists and producers, McIntosh has come to represent performance and reliability. All components include that iconic blue Watt output meter synonymous with high-end sound. Ready to unleash the magic behind some of the most iconic moments in music history including Woodstock and The Grateful Dead's Wall of Sound?

Get the best sound performance for 2-channel, theaters or distributed audio with McIntosh. Its handcrafted products include amplifiers, preamplifiers, phono preamplifiers, receivers and home theater processors. The company has offered its revered electronics since 1949 and expanded its range with speakers in the 1970s. And in recent years, it's added an even more intimate approach to high-end audio with its headphone amplifiers featuring built-in DACs.

Their various products make it easy to design systems that best match your listening preferences and budgets. However you like to listen or wherever your music lives, it's possible to listen just as the artist intended with the help of McIntosh components. Enjoy the purest sound reproduction with two-chassis preamplifier designs like the C12000 the perfect pair for your vinyl records. Take control of your digital sound to new heights with their DACs featuring Hybrid Drive solid state and vacuum tube technology.

As a nationally recognized leader in the field of high-end audio and home theater, Overture is a proud dealer of McIntosh audio components, selling customers the best audio components from McIntosh in Sales Tax Free Delaware. Interested in purchasing a new McIntosh product? You can trade-in any component towards a McIntosh component by filling out Overture's Trade-In Form.