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
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
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
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
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.
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
McIntosh C22/MC75 System Ratings
McIntosh MC75 Vacuum Tube Monoblock Amplifier
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