November 2015

McIntosh MC75 Monoblock Tube Amplifier And C22 Tube Preamplifier
McIntosh's latest re-introduction of their classic audio components.
Review By Anthony Nicosia

  McIntosh has been making high-end audio products that music lovers have treasured for a very long time. This review of McIntosh's re-introduction of their MC75 monoblock tube amplifier and C22 tube preamplifier ($3750 and $6000 respectively) shows the strength of this longstanding high-end audio manufacturer. Originally founded in 1949 they operated out of Silver Spring, Maryland until 1956 when they built their current facility in Binghamton, New York. What can anyone say about McIntosh Labs that has not already been said? This sixty-six year old company has produced many classics and is still making gear audiophiles crave for even in today's highly competitive world-wide market. Let it be known that my passion for McIntosh audio gear has spanned decades. In the past my home has seen the MC275, MC240, MC225 (two of them to be exact), MC2102, MC2105 and MC452 amplifiers. There has also been a C28 and C26 preamplifier as well as an MR67 tuner in my system. As of this writing some are still in my system and if time could be turned back I would have kept them all. Even during periods when I did not own a McIntosh it always ran through my mind to purchase one whenever any of these beauties fell into my line of sight. Sure, we are not supposed to choose audio equipment based on how pleasing it is to the eye but when that package includes both great performance and looks then as they say, all bets are off.

It is easy to believe the claim that McIntosh brought back the C22 preamplifier and MC75 amplifier because of popular demand as they have quite a large worldwide following. In fact it took me months to get my samples as they were backordered and the factory unable to spare me the necessary units for review. Using today's technology and modern features while retaining a nostalgic look it is easy to see how the C22 and MC75 could deliver a winning combination that both older and younger audiophiles alike will enjoy. The question before us today is do they have enough of what it takes to join that elite group of select McIntosh gear audiophiles have treasured over so many decades. Both pieces are of a tube design, the C22 a full function tube preamplifier with remote control and phono stage included while the MC75 is a mono block tube power amplifier. As you shall soon discover, it is my belief that the answer to that question is a resounding YES!

McIntosh C22 Vacuum Tube Preamplifier
Looking at the C22 tube preamplifier one is immediately struck with a sense of nostalgia as its front face plate is similar in design to that of the original C22 which was manufactured from 1963-1968. Unlike its predecessor though this little beauty has some enhanced designs to help move it into the 21st century. Hitting the highlights on the front faceplate you will find separate tone controls for bass and treble. If that is not your cup of tea then just flip the tone bypass switch and the tone controls are taken out of the loop or of course just leave them set to neutral.  If you are into vinyl playback, and I hope you are, there are two knobs to adjust phono loads for moving magnet or moving coil cartridges. Then there is a knob for balance control, to adjust between the left and right channels, as well as one for mode selections. The mode selector permits the owner to listen to various channel combinations ranging from stereo to mono. If you are into recording you will enjoy the switch that lets you monitor the recording in real time. Perhaps listening at softer volume levels late at night is your thing, then you might want to try the loudness switch or maybe use the headphone jack so as to listen quietly by yourself. Of course an input selector and volume control knob are present as well. The remote control was one of the better ones I have used as it fit quite comfortably in my hand while controlling many of the C22 functions. It was neither small nor flimsy but rather had a good weight to it making me feel I was holding something quite substantial.

Taking a peak at the rear of the C22 I was pleasantly surprised to find one balanced and two unbalanced pairs of outputs for connections to amplifiers plus two more sets of balanced inputs to connect D/A and CD inputs. There are also unbalanced inputs for sending signals to a recording device and six more unbalanced inputs for phono, auxiliary, DVD, D/A, CD, tuner, Phono Moving Magnet and Phono Moving Coil cartridges. Speaking of vinyl the C22 did not forget to include ground terminals for the ground wires for not one but two turntables. Then there are outputs to connect the C22 to other McIntosh gear enabling it to use the remote to turn them all on and off at the same time, a welcomed feature. The C22 has a power outlet enabling you to choose between the factory power cord and an appropriate one of your own choice. Inside the C22 you will find two of the six 12AX7a tubes used for the moving magnet phono stage, two for the moving coil circuitry and two dedicated to high level circuitry (the line stage). This latest C22 also sports electromagnetic input-switching for reliable, noiseless, distortion-free operation usually running less than 0.08%.

McIntosh MC75 Vacuum Tube Amplifier
The McIntosh MC75 is a single channel tube power amplifier which I suspect most will use in pairs within a stereo system setup. Others of course might decide to put it into a mono system or perhaps even use three or more for an elaborate home theatre operation. For the purpose of this review the MC75's were used as a pair in my two channel stereo room. When facing the front of the MC75 one sees the traditional "McIntosh 75" raised logo in silver against a black front faceplate, reminiscent of the original MC75 sold from 1961-1970. Instead of the older chrome chassis which tended to rust after forty odd years (although my well cared for two MC225's have almost no surface rust), the new MC75 sports a front deck made of stainless steel with what McIntosh calls a "Super Mirror Finish" . There is one12AX7A input/phase inverter tube, two 12AT7 voltage amplifier and driver tubes plus two KT88 Power Output tubes (with Air-Pipe cooling at their respective bases) all located atop that beautiful polished stainless steel deck. McIntosh has provided the MC75 with Ceramic tube sockets equipped with gold plated contacts to help protect them from atmospheric contamination. Also included with the MC75 is a tube cover or as many refer to it as, a tube cage. The company recommends leaving it on in order to protect you from the hazardous voltages inside the MC75. This is especially good if you have small children, pets or curious people around who have no idea how hot tubes can get or how dangerous a tube amplifiers voltages can be. For me though anything that covers those magnificent looking glowing tubes is considered sacrilegious, besides my children are grown, pets non-existent and visitors fully aware not to touch my audio gear.

If you are new to tube amplifiers with the MC75 you do not have to worry at all about tube biasing the output tubes for you see this is a self-biasing amplifier. So when you need to replace a tube or tubes just drop it in and you're done. Why you can even switch over to 6550 tubes instead of KT88's and still there is nothing to adjust; now you cannot get any simpler than that. In the background behind the tubes of each amplifier are one large power transformer and an equally large output Autoformer that help the MC75 coax as much power and dynamics as it can from the two KT88 tubes. Those Multifilar Wound Output Transformers are part of McIntosh's patented Unity Coupled Circuit and said to extend tube life and frequency while lowering distortion. The following was taken from a McIntosh brochure for their MC2102 tube power amplifier (same circuit as found in the MC75) and seemed to sum up their Unity Coupled Output Circuit design quite nicely, so here it is.

"Frank McIntosh and Gordon Gow invented and patented the McIntosh Unity Coupled Output Circuit. Two features differentiate from other designs. First, the output tubes deliver power from both their plates (anodes) and their cathodes, not from their plates alone as in conventional circuits. Second, the output transformer's two bifilar primary windings give it one-half the turns ratio of conventional transformers, equating to one-fourth the impedance ratio. This allows a close coupling of the primary and secondary windings, resulting in wide bandwidth, flat frequency response, and low distortion."

Moving over to the unit's right side, you will note some lettering and one AC outlet where you can either use the factory supplied power cord or one of an aftermarket variety as long as it is compatible. The left side is where you will find your speaker and balanced or unbalanced connections. The gold plated connectors and tube socket contacts with gold plated input jacks and output binding posts are an excellent finishing touch. Input sensitivity can be adjusted with a sliding switch to either 1.7 or 0.85 volts to match your preamplifiers or audio video control centers output voltage capability. On that left side you will find a power on/off switch and connecting the MC75 to other McIntosh gear can be done via a power control input switch. This is helpful when turning on an entire system remotely. Lastly there is a very small light next to the power switch. Please do not overlook this seemingly insignificant little light as it is actually quite important. Here is a quote from the owner's manual that will explain its function in detail.

"The MC75 Sentry Monitor Tube Protection Circuitry provides protection to the Power Amplifier in the event of an impedance mismatch (1) between the MC75 and the Loudspeaker. It will also activate if there is a short circuit at the MC75 Output Terminals (or the Loudspeaker Terminals) or if a MC75 Power Output Tube should fail. During normal operation the Sentry Monitor Tube Protection Circuitry has no effect on the performance of the Power Amplifier. In the event a problem occurs, the MC75 Sentry Monitor Tube Protection Circuitry will activate to prevent potentially destructive high levels of current from flowing in the amplifier. The Front Panel Standby LED will start flashing indicating the Protection Circuitry has activated and the AC Power to the MC75 is halted."

"(1) The impedance of a Loudspeaker actually varies as the Loudspeaker reproduces different frequencies. As a result, the nominal impedance rating of the Loudspeaker (usually measured at a midrange frequency) might not always agree with the impedance of the Loudspeaker at low frequencies where the greatest amount of power is required. Contact the Loudspeaker Manufacturer for additional information about the actual impedance of the Loudspeaker before connecting it to the McIntosh MC75."

It really was nice to see the MC75 coming with a power on/off switch, balanced inputs and loudspeaker binding posts that allow for larger spade connectors and/or banana plugs, all missing from the original design from the sixties and certainly most welcomed for today's users.

Playing Together As One
It has been awhile since I last heard Tracy Chapman and I remember being fond of her more recent Our Bright Future [Elektra 514061-2] CD. The C22/MC75 combo could not have made me happier as it aided in creating an overall very life-like presentation with respect to both vocals and instruments. There was a beautiful "you are there" quality to the music as Tracy Chapman sang "Thinking of You". There was a moment when the drummer tapped the rim of the drum set with the sticks rather than on the skin which immediately got my attention. It sounded so real as to make me stop and wonder if that was coming from the recording or actually from a sound within my room. Of course I know that was not the case but that was how clearly realistic it did sound. The album seemed over rather suddenly as if only moments went by from start to finish. High quality tube gear has a way of making time pass rather quickly as one gets lost within the music's spell rather than being distracted by the gear itself. Poor or mediocre quality tube gear has a way of making one reach for the off-button even sooner and I avoid them at all costs. My feeling is to either get something that makes you sit up and take notice or move onto something else of better quality, whether solid-state or tube in design. Luckily McIntosh has both of those available, tube and solid-state, to fit your personal needs and in a perfect world my recommendation would be to buy one of each. The opening short musical passage of acoustic guitar and piano on "For a Dream" was heavenly as the C22/MC75 combination established an overall tranquil feeling for the song which was a tough act to follow. Top notch audio gear has a way of setting the stage for the mood performers intended and make no mistake this preamplifier/amplifier combo is definitely of high quality.

For those of you who have yet to hear Philip Glass's Solo Piano [CBS MK 45576] doing so for the first time with the aid of this duo from McIntosh just might spoil you. The piano being difficult for a home stereo to accurately reproduce seemed no challenge at all from the very first to the final note on this CD. The piano sounded full size and the inner details of the music were beautifully laid bare before me. Truth of timbre was so strong I forgot my loudspeakers were there and just enjoyed this incredible event with all the emotionally attachment a live performance could elicit. Switching now to something completely opposite of a solo piano to the Queen Greatest Hits [Hollywood Records 2061-62465-2] CD the opening finger snaps on "Killer Queen" sounded just perfect. As for those lower bass notes on "Another One Bites the Dust" they were tight and clear.  "We Will Rock You" literally rocked my room when cranking up the volume to the loudest level my ears were comfortable with. Air Supply is still going strong and their album Live in Hong Kong [Evosound EVSA275A] is a good testament to this. My wife's favorite song being "The Power of Love", which played at our wedding as she walked over to stand beside me to recite our vows, is also on this album. Here everything sounded right, the audiences quiet reaction at the opening where you could hear layers of rows of people applauding, the sound of thunder shortly after and of course vocal timbre to melt your heart. In our family if you cannot do this song justice, it's see you later. Needless to say the McIntosh C22/MC75 duo did it all just right.

High Quality Phono Stage
My Lyra Delos stereo cartridge is of a moving coil design and not having a moving magnet cartridge on hand the comments on the C22 phono stage is limited to its moving coil input. It has been a long time since I heard Richie Havens in person, yet listening to his Something Else Again ([Verve Forecast FTS 3034] vinyl record through the McIntosh C22/MC75 gear was like being back again. Saying the soundstage was wide, soundscape depth deep and tonal quality excellent just does not do the experience justice. Audiophile terms are a way we use to describe an event but no matter how much a person can for example explain to another the taste of an apple, only through direct experience can one truly grasp the reality of its taste and texture, alas the dilemma of the reviewer. So please if you can find a dealer or friend with this preamplifier/amplifier setup, do go listen for yourself. Even my wife was impressed when hearing how deep and tight the bass felt on Donald Fagen's Morph the Cat [Reprise 49975-1]180 gram vinyl two record set. Speaking of "being there", the sound of Yusef Lateef and his group was spot on from his The Golden Flute [Impulse A-9125] record. It had been long since hearing him in a small club in San Francisco back in the 70's. Yet here again this McIntosh combination lent a good sense of intimacy to the performance and with the lights off brought me for a moment back to that club with my friends and it felt ever so good. A great example of the layering of performers came when listening to the both male and female choir members on the J.S. Bach Magnificat in D/Cantata No. 51 [Nonesuch Records H-71011] album. Wow did my speakers disappear as the room filled up with the sound of voices layered nicely left to right and front to back. It was so good that in the end I was looking for my ticket stub to save as a souvenir.

It is always a pleasure to hear Stevie Ray Vaughan and Double Troubles version of The Beatles song "Taxman" on their Greatest Hits album [Epic Stereo E 66217]. Here once again this McIntosh system did not disappoint.  They once again amazed me with their ability to make music "come alive" making for an exciting listening session. This is not a slow pondering tube setup but rather quite quick, expansive in its presentation of performers onstage, inner detail is excellent and sounded better (up to a point naturally) as the volume increased. By the way, I loved those tone controls and adjusted each depending on the type of music or my own personal mood. With this particular album the bass control was set to plus 6 and treble at plus 4 (out of a minus 10 to a plus 10 range). What is so great, like with tube substitutions is that you can quickly and easily adjust the sound to your liking. As for vocals, well the "boys" sounded great, meaning The Beatles from their Hey Jude [Apple SW-385] record. On "Paperback Writer" each member of the group was clearly defined within individual spaces in the soundscape so as to be heard as distinctly separate persons. Paul McCartney releasing a wild scream on "Can't Buy Me Love" emphasized the systems strength of drawing one deep into the music.

If you are wondering if tube rolling came into play, well of course it did, silly you. My belief is that my review process should really only center on stock equipment and even tube rolling kept out of the mix except for maybe a brief mention sometimes. Tube rolling did occur though with the MC75. Here the stock KT88 tubes were replaced with some original vintage Genalex KT88's and the 12AX7A's switched out for Telefunken12AX7's or Sylvania triple mica black plate 5751's, depending on my preference at the time. As for the 12AT7's, I am in the process of purchasing either Mullard CV4024's or 6201's. So many choices so much fun, that's tube gear for you. While it never felt anything less than amazing when listening to the stock factory tubes, substituting the above did take my experience to another level, albeit at a higher cost. Luckily all the tubes except for the 12AT7's were already in my possession, saving me from spending a lot of additional money. If there were enough funds left over in my audio jar I would have purchased both the C22 and MC75 complete setup. Unfortunately it was not too long ago that I purchased a new preamplifier and with only limited funds left for audio purchases I could only buy the MC75. It really was a tough call as my fondness for the C22 had me going back and forth as to which one to buy and it would not surprise me if one day it finds its way back in my system.

In The End, All That Truly Matters Is Did You Enjoy The Music.
Yes I Did!!!
Tube gear has this way of presenting a "magical" mid-range that is difficult to reproduce, even much more expensive solid-state gear. Those who love listening to music through tubes swear there is nothing better. I have not recently counted but am sure I have over one hundred "spare" tubes of excellent quality and rarity in storage awaiting their turn in various gear. Yes, I am a tube roller and if there was a support center for us my wife would surely sign me up. In fact I wish she would so tube enthusiasts like me could meet to swap or purchase even more tubes from one another on the pretense of meeting for therapy. Being a hopeless tube audiophile, reviewing tube gear could not make me happier. There is something about not only the glow from tubes but also that extra connection one gets with audio gear when changing them to fine tune the sound to your taste and system that is just so much fun.

The McIntosh C22 tube preamplifier delivers a lot for $6000. You get a well-designed remote control unit; tone controls to tailor fit the sound to your room and a high-end phono stage for not only moving magnet but moving coil cartridges as well. The C22 also has selectable resistance and capacitive loading to aide in matching phono cartridge and turntable. Inside you will find six 12AX7a tubes and electromagnetic input-switching for reliable, noiseless, distortion-free operation (usually running less than 0.08%). Basically what you are getting is a retro styled C22 but with modern updated technology.

Being a mono amplifier the MC75 will provide the ultimate in stereo separation being that each channel will have a separate amplifier driving it. At 75 Watts of power output into a 2, 4 or 8 Ohm loudspeaker with less than 0.5% distortion the MC75 has ample power to drive most loudspeakers and my Wilson Audio Watt/Puppy speakers were more than happy being paired to them. These amplifiers came standard with a tube cage, XLR/RCA inputs, Sentry Monitor Tube Protection Circuitry and Multifilar Wound Output Transformers (which are part of McIntosh's patented Unity Coupled Circuit) to extend tube life and frequency while lowering distortion. You get all this and more for only $7500 a pair, or $3750 apiece.

One thing that always concerns me with tube gear is noise but with these two units it never became an issue. This combination of C22 preamplifier and MC75 amplifiers was a joy to have in my home. Not only did they sound marvelous but their throw-back look took me back to a time of my youth that was wonderful to remember. While it is impossible to go back to those days it certainly is possible to purchase these units with which to enjoy music today. Buying older McIntosh gear is fun but here with this combination you need not worry about restoring the units physically or electronically and guess what? They come with a McIntosh factory warranty and to me that means a great deal. If pushed to sum up my experience with the C22 and MC75 in just one word it would have to be "amazing". I loved them both and each one gets a big thumb up! Bravo to the people at McIntosh Labs.

The Listening Environment
The review room is eighteen feet eight inches long by thirteen feet wide with loudspeakers and equipment kept on the short wall. The cathedral ceiling starts at eight feet on the short wall slopping upwards to reach a height of thirteen feet in the middle than returning to eight feet at the opposite end. The hardwood floor is partially covered by a nine by six foot oriental rug lying down the long ways facing toward the loudspeakers, placed dead center between but not under the listener or the audio rack. The room has no doors but there are two openings. One opening is in front of the right loudspeaker on the long wall giving access to the hallway the other behind the listening position to a formal dining area. There are two large floor standing GIF Tri-trap acoustical panels one in each corner of the short wall in front of the listener and two panels from Acoustic Revive (AR) located on the wall directly behind each loudspeaker. A third AR panel is placed about two feet behind the listener's chair. Numerous Auralex Studio foam squares are placed along walls and high up in each of the four corners of the room. All the audio equipment is located in a Synergy Twin S30 Salamander audio rack placed about a foot away from and in the middle of the short wall opposite the listening position.

Review Equipment
McIntosh MC75 Mono Tube Amplifiers
McIntosh C22 Tube Preamplifier
Wilson Audio Watt/Puppy 5.1 Loudspeakers 
Loudspeaker Cables: Acoustic Revive Single Core Loudspeaker Cables
Electrocompaniet EMP-1/S Balanced Multiformat Player 
VPI Classic 3 Turntable
Lyra Delos Moving Coil Cartridge 
Musical Surroundings Nova Phonomena Phono Stage (with new custom factory upgrades)
VPI MW-1 Cyclone Record Cleaning Machine
Audience aR2p-TO Power Conditioner 
Acoustic Revive RPT-4 Ultimate Power Supply Box 
Cherry Synergy Twin S30 Salamander audio rack
Various Acoustical Room Treatments

McIntosh C22/MC75 System Ratings
The following was how I rated the equipment based on a rating system that does not take into consideration the cost of the product, until the very last question, "Value For The Money". Before that all products are rated against others in its category, regardless of financial consideration with the highest rating being 5.

Specifications
McIntosh C22 Vacuum Tube Preamplifier 
Ultra Low Distortion: 0.08%
Frequency Response: +0, -1dB from 10Hz to 100kHz
Maximum Volts Out (Balanced / Unbalanced): 16/8 V RMS
Input Impedance (Balanced/Unbalanced): 20K Ohm, 20K Ohm
Phono Voltage Gain: 60dB
High Level Voltage Gain: 15dB
Signal to Noise Ratio: 98dB
Tubes: Six (12AX7a tubes)
High Level, 450mV unbalanced, 900mV balanced 
Phono MM, 4.5mV 
Phono MC, 0.45mV 
Signal To Noise Ratio (A-Weighted): 
High Level, 98dB 
Phono, 80dB 
Input Impedance:
High Level, 20K ohms unbalanced, 20k ohms balanced 
Phono MM, 47K ohms; 50 to 350pF, in 50pF steps 
Phono MC, 10, 25, 50, 100, 200, 500 or 1,000 ohms; 100pF 
Maximum Input Signal: 
High Level, 5V Unbalanced, 10V Balanced 
Phono MM, 50mV Phono, MC, 5mV 
Voltage Gain: 
High Level to Record Output: 0dB 
High Level to Output 1 and 2: 15dB 
Phono MM to Record Output: 40dB 
Phono MC to Record Output: 60dB 
Output Impedance: 220 ohms 
Headphone Load Impedance: 16 to 250 Ohms 
Tube Compliment: Two each 12AX7A, 12AX7A for MM phono and 12AX7A for MC phono
Dimensions: 17.5" x 6" x 18" (WxHxD)
Weight: 27 lbs. (12.25kg)
Warranty: three years from the date when it was purchased from an Authorized McIntosh Dealer, except for vacuum tubes which are covered under a 90 day warranty
Price: $6000

McIntosh MC75 Vacuum Tube Monoblock Amplifier
Power Output: 75 watts into 2, 4 or 8 Ohm loads
Output Load Impedance: 2, 4 or 8 ohms
Frequency Response: +0, -3.0dB from 10Hz to 100,000Hz
Total Harmonic Distortion: 0.5%
Input Sensitivity (for rated output): 1.7 Volt or 0.85 Volt Unbalanced, 3.4 Volt or 1.7 Volt Balanced
Signal To Noise Ratio (A-Weighted): 110dB below rated output
Intermodulation Distortion: 0.5% maximum
Wide Band Damping Factor: Greater than 18
Input Impedance: 20,000 ohms Unbalanced, 15,000 ohms Balanced
Tube Compliment Per Monoblock: 12AX7A, two 12AT7 and two KT88
Overall Dimensions: 17.75 x 8.5 x 8.5 (WxHxD)
Weight: 38 lbs.
Warranty: three years from the date when it was purchased from an Authorized McIntosh Dealer, except for vacuum tubes which are covered under a 90 day warranty
Price: $3750 each

Company Information
McIntosh Laboratory, Inc.
2 Chambers Street
Binghamton, NY 13903

Voice: (607) 723-3512
Fax: (607) 724-0549
Website: www.McIntoshLabs.com