AudioAficionado.org - McIntosh MC601 Review

by J. Dan Daniell

https://farm5.staticflickr.com/4465/...e64585c7_z.jpg

I first began to fantasize about owning McIntosh MC601 amplifiers in January of this year after the CES show. The seed was planted when the first photos were posted and conversations about the 601 began to generate a healthy buzz. I continued to read about and discuss these gorgeous amps, and as the months past the seedling grew until fruit was born. Two McIntosh MC601 mono block amplifiers now grace my main sound system with their presence and have permanently replaced the wonderful MC501’s I have enjoyed so much.

McIntosh has been quietly introducing amplifiers that reflect a new direction for the typical McIntosh house sound. As I now understand it, it began with the introduction of the MC2Kw and 1.2Kw amplifiers, continuing to the MC2301 tube mono blocks, and has progressed to the newest McIntosh amplifiers, the MC452 and the MC601 mono block. The amplifiers mentioned, with the exception of the MC2301 tube power amplifier and the MC1.2Kw, now have the advantage of ThermalTrak transistor output devices. Each ThermalTrak transistor is able to adjust its own bias voltage continuously in real time based on its actual operating temperature at any moment, thus ensuring optimum low noise performance and vanishingly low distortion specifications. I suspect the new amplifier circuit designs also use a number of upgraded parts in the signal path, and may even sport new audio circuits all together. Whatever McIntosh engineering has done to the newest stable of amplifiers, the changes have created an audible improvement in performance and represents a new distinction for the traditional McIntosh sound.

Once the MC601’s were installed in my main system rack, I double checked the slide switch on the amplifier’s rear apron that selects balanced or unbalanced interconnects. I have it set to balanced since I am using balanced Wireworld Silver Eclipse 6.0 interconnects between the C1000P preamp and the MC601’s. During the break in period I removed the MEN220 from the signal path between the C1000P and the MC601’s, although I am still using the MEN220’s active crossover function between the preamp and the JL Audio Fathom f113 subwoofer. Both MC601 amplifiers are powered by a PS Audio Power Plant Premier AC regenerator using two meter Wireworld Silver Electra power cords. There are two Power Plant Premiers in the main system, each fed from separate dedicated 20 amp circuits. One Power Plant Premier feeds the two 601's, and the other Power Plant Premier feeds the preamp and source components.

Installing the MC601’s on the same shelves in place of the MC501’s required relocation of two 120mm 12 volt DC cooling fans mounted on the rear shelf edges. The new amplifier depth is 22 inches, and consumes the entire rack’s bottom shelf depth front to rear. The MC601’s are big, with the cooling fins installed on the sides of the amplifier versus the rear mounted cooling fins on the MC501’s. After making the power and audio connections to each amp, and connecting the mini plugs for power control, I was ready to go. Pressing the Standby button on the preamp immediately powered up the entire sound system. My first impression was how beautiful the larger meters look on the face of the MC601’s, and how mesmerizing the needle movements are once the music begins. The new meters are exceptionally alluring surrounded by polished black glass and attractive anodized aluminum handles.

When I began to play music with the MC601 amplifiers I had a preconceived notion they would mimic the break in performance I experienced with the recently installed MC452 amplifier in the studio system. The MC452 went through a bright sounding period that lasted more than 50 hours before gradually settling into its permanent voice that is now smooth, detailed, and liquid. I was actually dreading the possibility of going through this process again with the MC601’s, but the bright period never materialized. What I experienced surprised me. From the first minute the amps began to pass sound, the 601’s exhibited a firmer grip on the PMC EB1i’s woofers. To make sure I was really hearing what I thought I was hearing I turned the Fathom f113 subwoofer off. Sure enough, the bottom octaves coming from the PMC woofers clearly had a new found definition, demonstrating a faster pace on initial bass note attacks, while at the same time revealing rapid bass note changes without a hint of overhang or smear. It has now been 51 hours since the initial power was applied to the amplifiers and the same sense of firm control and quickness is still apparent, but not just with the bass as first noted. The quicker pace is now undeniable throughout the entire midrange as well. The McIntosh sound we know and love is still thoroughly woven through the core of the MC601’s character, but to use an analogy, the weave of the fabric is now tighter, smoother, and woven from a silkier thread. The new amplifier’s pace is such that the essence of real performers and instruments glisten in imagined holographic images that are clear and deep. These visions literally hang in open space between my speakers where I now find it easier to use far less imagination to arrive at full blown illusions of musicians, vocalists and instruments in my room. The sensation of real music with all of its transparency, perfect timing, immense resolution and unbridled dynamics is wholly exhilarating. Add to this a pure deep velvet blackness of absolute background silence from which the faintest of audible nuances can be discovered, and the total combination of sonic pleasures become proof that the MC601 is an amplifier to be revered.

I have been on a CD and SACD playing frenzy since installing the MC601’s in the main system. Not once have I listened to the MS750 or vinyl since installing the new amps, only the MCD1100. My reasoning is I want to use only the very best source available to me while I evaluate the new amps. I want unwavering consistency from the source component. The many variables in source recordings are what they are, but the source component must remain coherent and true. I have played everything from classical violin to jazz guitar, from female vocals to raspy blues, from solo acoustical piano and guitar to hard rock electric guitar and raw power drum solos. I kept searching for a disc that might uncover some hidden flaw in the amplifier’s ability to portray a believable and completely engaging performance. I have failed to uncover that flaw, and now believe my search was in vain. I am not trying to say I have discovered the perfect amplifier, but the McIntosh MC601 is as near perfect as any amplifier I have ever owned. Does the MC601 slay the MC501? No, but there is no denying the MC601 adds a fresh measure of pace, rhythm and timing to the mix that cannot be ignored, even by seasoned die hard 501 owners. Remember, I was a happy and satisfied MC501 owner, too.

Not only is the MC601 a flamboyant visual knock out with its return to a smooth black glass face, new tapered handles and large blue meter, it now delivers a sweeter voice that’s as pleasing and enchanted as a sparrow’s song on the window ledge. It whole heartedly lives up to a live quartet performance in a smoky jazz club, a full blown rock concert, or the huge crescendo of a large orchestra in all its grandeur. Everything is present. The purity of the 601's sonic signature is a fresh step in the right direction from previous McIntosh amplifiers I have owned and loved. The new amplifier leaves me wanting for only one thing, more time in front of my speakers. Yes indeed, the new McIntosh MC601 amplifiers are as good as you’ve read about, and then some. There is one big drawback. Turning the MC601 amplifiers off in the wee hours of the morning is now more difficult than ever before.