New McIntosh MC901 Dual Mono Amplifier

[jimimac]

Has anyone in the group purchased A pair yet?? It's gonna be hard to sneak them past the wife��.Just tell her that you are auditioning them.Or you got A really great deal that you couldn't say no to??? Wait Wives don't read my posts right. Sorry Ma'am ������������

[rob725]

The trick is a basement entrance! I like them a lot with the 1.1 speakers. The tube section for tweeter/midrange is much sweeter, smoother but with no loss of detail. I did feel like they lost some authority down low compared with the 1.25s. So I am not sure I would pick the 901s over the 1.25s if choosing between them. So I didn't. I'm using with the 1.25s in a tri-amp configuration, since the 1.1s support it. Sounds amazing!

[Masterlu]

Originally Posted by rob725

The trick is a basement entrance! I like them a lot with the 1.1 speakers. The tube section for tweeter/midrange is much sweeter, smoother but with no loss of detail. I did feel like they lost some authority down low compared with the 1.25s. So I am not sure I would pick the 901s over the 1.25s if choosing between them. So I didn't. I'm using with the 1.25s in a tri-amp configuration, since the 1.1s support it. Sounds amazing!

First Class or stay home!

[rob725]

I don't know; compared to $18K a pair power cables, keeping the amps seemed like a bargain, lol.

[Masterlu]

Originally Posted by rob725

I don't know; compared to $18K a pair power cables, keeping the amps seemed like a bargain, lol.

[Charles]

Originally Posted by rob725

The trick is a basement entrance! I like them a lot with the 1.1 speakers. The tube section for tweeter/midrange is much sweeter, smoother but with no loss of detail. I did feel like they lost some authority down low compared with the 1.25s. So I am not sure I would pick the 901s over the 1.25s if choosing between them. So I didn't. I'm using with the 1.25s in a tri-amp configuration, since the 1.1s support it. Sounds amazing!

How do you like the new 1.1's. You are the first person I have know to have them. Is your system up somewhere where I can see it? How is your bass with the 6" woofers? You certainly have an impressive/beautiful system. I'd love to hear any Mac speaker, especially the 2.1 or 1.1

[eljr]

Originally Posted by Masterlu

Announcing the McIntosh

MC901 Dual Mono Amplifier

McIntosh is proud to announce the new MC901 Dual Mono Amplifier.

Legendary home audio company McIntosh has been perfecting vacuum tube amplifiers since the 1940s and solid state amplifiers since the 1960s. Their 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 they could dream of, design and build as the ultimate solution for bi-amping loudspeakers: the new 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 McIntosh's 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 McIntosh's 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 the 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 the user to optimize the performance of both amplifier sections to their 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 audio. And just like the MC901 itself is a new design, so too is its meter with the introduction of McIntosh's new DualView™ Power Output Meter. The DualView meter features two of McIntosh's 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® 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.

A brand new technology in the 300 Watt vacuum tube amplifier section of the MC901 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.

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.


Unit Dimensions (W x H x D):
17-1/2" (44.5cm) x 13-1/4" (33.7cm) x 29-1/2" (74.9cm)

Shipping Dimensions (W x H x D):
24-13/16" (63cm) x 18-3/8" (46.7cm) x 36-1/4" (92.1cm)

Unit Weight:
170 lbs (77.1 kg)

Shipping Weight:
190 lbs (86.2 kg)

Expected to begin shipping December 2019

• US MSRP: $17,500 each Mono Amplifier

A one-of-a-kind, ultimate solution for bi-amping loudspeakers with dual inputs

very very cool.... to bad I am no longer in this market

[rob725]

Originally Posted by Charles

How do you like the new 1.1's. You are the first person I have know to have them. Is your system up somewhere where I can see it? How is your bass with the 6" woofers? You certainly have an impressive/beautiful system. I'd love to hear any Mac speaker, especially the 2.1 or 1.1

Charles,

I really like the 1.1s. The 4 6.5" bass drivers put out very tuneful and authoritative bass and go low. I have been breaking everything in (while constantly tweaking, cabling, power conditioning...thanks to places like this and people like Ivan ) for a few months, so it all keeps getting better. Soon, I will calibrate the amps with software/mic and will post the frequency response in my room along with pics.

They of course have slam and are great for HT. But the assumption of "wall of sound" over pinpoint imaging that some make sells them short. It's true there is a wall of sound that gets to every seat of the theater. But in any one seat (esp. my seat, which is in the sweetest spot), I don't hear a wall, I hear great imaging where the performers feel like they're in the room. They, like the amps, seem effortless. The only issue I had was that the system was a bit shrill at around 2500 hz (not sure if it was 1.25s or 1.1s or c53) so turning things up could be a bit painful, which I was able to address with the C53 EQ. But now, with the tubes covering that range (and likely the cable, conditioning and isolation upgrades), everything has fallen into place (EQ no longer needed), and I can't wipe the stupid grin of my face. I'm afraid my wife might think I'm hiding another woman in the theater, as I spend so much time enjoying the system!

I'm in north-central Arkansas, so not real close to anywhere, but always happy to have someone come and audition. I had to buy new 1.1s, 1.25s, and c53 on a bit of faith (although I have a great Mc Dealer who would work with me if I didn't like them-as well as knowing McIntosh resale value is strong) as there were no or very few reviews of any of them, although the 611s and c49 and c52 were well reviewed.

[Charles]

Originally Posted by rob725

Charles,

I really like the 1.1s. The 4 6.5" bass drivers put out very tuneful and authoritative bass and go low. I have been breaking everything in (while constantly tweaking, cabling, power conditioning...thanks to places like this and people like Ivan ) for a few months, so it all keeps getting better. Soon, I will calibrate the amps with software/mic and will post the frequency response in my room along with pics.

They of course have slam and are great for HT. But the assumption of "wall of sound" over pinpoint imaging that some make sells them short. It's true there is a wall of sound that gets to every seat of the theater. But in any one seat (esp. my seat, which is in the sweetest spot), I don't hear a wall, I hear great imaging where the performers feel like they're in the room. They, like the amps, seem effortless. The only issue I had was that the system was a bit shrill at around 2500 hz (not sure if it was 1.25s or 1.1s or c53) so turning things up could be a bit painful, which I was able to address with the C53 EQ. But now, with the tubes covering that range (and likely the cable, conditioning and isolation upgrades), everything has fallen into place (EQ no longer needed), and I can't wipe the stupid grin of my face. I'm afraid my wife might think I'm hiding another woman in the theater, as I spend so much time enjoying the system!

I'm in north-central Arkansas, so not real close to anywhere, but always happy to have someone come and audition. I had to buy new 1.1s, 1.25s, and c53 on a bit of faith (although I have a great Mc Dealer who would work with me if I didn't like them-as well as knowing McIntosh resale value is strong) as there were no or very few reviews of any of them, although the 611s and c49 and c52 were well reviewed.

Absolutely terrific!! And did I understand you that you are using both 901's and 1.25's? I hope Ivan will help you get pics up. I would love to come and hear your system. It is very difficult for me to travel but I appreciate the invite very much. How is the build quality of your Mac gear, especially the 901's and the 1.1's? What a system!

I think it's amazing how Mac can get this type bass out of small woofers. I am sure their transient response must be superb making for a wonderful upper bass which systems with large woofers struggle with. I'm a big fan of the column approach.

[rob725]

Originally Posted by Charles

Absolutely terrific!! And did I understand you that you are using both 901's and 1.25's? I hope Ivan will help you get pics up. I would love to come and hear your system. It is very difficult for me to travel but I appreciate the invite very much. How is the build quality of your Mac gear, especially the 901's and the 1.1's? What a system!

I think it's amazing how Mac can get this type bass out of small woofers. I am sure their transient response must be superb making for a wonderful upper bass which systems with large woofers struggle with. I'm a big fan of the column approach.

Correct, so I'm tri-amping. XLRs from c53 to 1.25s then XLR out from 1.25s to 901s. The 1.25s are driving the the 4 6.5" bass drivers, which handle up to 150hz. The 901 SS section drives the 2 6.5" midbass drivers - 150hz to 400hz - and then the 901 tube section drives the tweeters and midrange panel, which handles above 400hz.

I think a pretty similar result could be had a bit more economically by combining the 1.25s with the MC2301 300w tube monos and an external crossover, as the 1.25s could drive all six 6.5" bass drivers.