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McIntosh MHA100 Headphone Amplifier Review

McIntosh MHA100


McIntosh MHA100 Review: The MHA100 is perhaps the finest headphone amplifier currently in production. With an exceptional build quality and class leading performance McIntosh Labs have excelled themselves. This headphone amp has already become a legend in our books.

Review Preface:

With an extensive history spanning from pre-war telecommunications to commercial broadcasting and systems design, it was in the early 40’s that the obsessive perfectionist, Frank McIntosh, fantasised about designing a high performance audio amplifier. With amplifiers of their time being in audiophile infancy, the various unit designs in circulation were plagued with distortion and generally inadequate for detailed listening. It was only a few years later, in the mid 1940’s, that McIntosh hired Gordon Gow to help develop his vision. As expected, the passionate duo came up with an outstanding critical design aspect that was later named the Unity Couple Circuit. Born out of obsession, it was this distortion smashing invention that was patented by the perfectionist, McIntosh and, with his fastidious second-to-none attitude, the most advanced amplifier of its time was created. However, McIntosh did not just want to stop with just a single groundbreaking audio amplifier, he wanted to continue his plight for audio excellence. Subsequently a product line was born and McIntosh became established as the best of the best. In fact McIntosh were so advanced that when they developed the MC275 vacuum tube amplifier in the mid 60’s and, little did they know, that to this day it would still be in production. The tagline ‘legendary performance’ is certainly apt as McIntosh products have always been created to a standard, not a price.

Iconised by a pair of striking blue analogue VU meters, a black screen printed glass faceplate and, of course, a classic lime green logo, the American Hi-Fi specialists have kept their defining design aesthetic with the MHA-100, despite this being their first dedicated headphone amplifier device. Although smaller than the typical McIntosh system, this headphone amp is in fact a hybrid device with the inclusion of a high resolution up sampling DAC and a 100watt speaker amplifier at 50watts per channel. This is truly a beauty to behold and the Bingham based wizards have certainly not rested upon their laurels with the MHA-100 design as, just like any of their other products, this headphone amplifier has been designed and manufactured at their state of the art Bingham based facility.

Having not said this before, the MHA-100 may very well be the finest headphone amplifier currently in production as just five minutes with this monolith will render any audiophile into submission, despite its £4995.00 price tag!

Unboxing, Package Contents, and Presentation:

McIntosh are widely known for going to the the far ends of the earth to ensure that the purchaser receives an immaculate unit with absolutely no discernible faults and, certainly this instance, I can confirm that the MHA-100 follows this legendary principle. This is a never ending exhausting principle that begins at the very conception of design and follows its way through every step of assembly to eventually arrive in the hands of an avid audiophile without even the most microscopic blemish. To ensure that this standard is maintained through the shipping process McIntosh have cocooned the MHA-100 with a thick plastic wrap and entombed this inner structure by suspending it within a large staple reinforced triple cell wall shipping box.

Entering into the package is a simple affair and includes a basic bound manual, a plastic McIntosh branded terminal post nut wrench, ergonomic remote control (that requires two AAA batteries), and a single region specific 1.2m IEC. At first glance you might wonder why the wrench is plastic, and the reason is simple; to not damage the binding posts and ensure that the finish is not tarnished in any way. Although frivolous, it is important to note that the wrench itself is not easily damaged and will survive multiple uses. With regards to the remote control, McIntosh have chosen to rely on an infrared design to inhibit any unwanted radio frequency interference from the sensitive internal circuitry. With this said it functions flawlessly across a large room in incandescent light and has a wedge shape form factor which comfortably rests in the upper palm. The remote control can control most features found on the faceplate of the MHA-100 with the exception of the variable output impedance and Headphone Crossfeed Director (HXD™).

Build Quality, Features, Function, and Usability:

Harbouring a comparably dinky little footprint of just 29.2cm x 14.1cm x 45.7cm to that of the ‘standard’ McIntosh separate, the MHA100 appears noticeably dwarfed and more designed for convenient ‘alcove’ placement rather than a traditional central HiFi plinth. I am pleasantly surprised that the McIntosh design team have clearly understood that any calibre of headphone amplifier cries out for a comfortable domestic placement that is, undoubtably, away from the traditional HiFi floor standing environment. With this said, stylistically, the MHA100 is not any less authentic as a result of these facts. McIntosh have paid their dues to the headphone loving gods and shared the same timeless design aesthetic that is so well loved across the product range. This high calibre execution extends to every corner of the device, however, the most instantly familiar quality is the black screen printed glass faceplate with the continuous glowing green McIntosh logo and seductive blue backlit bouncing analogue VU meters. It has to be said that the MHA100 has to be seen to be believed, all front panel features appear intuitive and intelligently labelled with buttery well metered stepped (to 0.5dB increments) and unstepped potentiometers, and beautiful push buttons which, by the way, use electromagnetic switching for an extended lifespan. McIntosh clearly build products to last decades without feeling so unsightly.

Located within the centre of the faceplate is a single blue dot matrix display that provides a simple click through menu system to control the various system parameters that appears to work with minimal complexity. This central menu system is intuitive and the classy blue stark contrast makes the system legible from a small distance away. Furthermore, the sharpness of this small screen is spot on as no ghosting or blurring of the pixels is evident, but the user has the option to tailor the luminosity of the screen for perfect environmental placement. In terms of usability, the navigation of the various parameters is controlled by the stepped potentiometers and settings can be engaged by clicking the potentiometer into the chassis. I can see no reason why navigating the MHA100’s settings would be difficult. Situated just above the dot matrix menu screen are a pair of the infamous McIntosh analogue VU meters. These VU meters are truly beautiful and appear to have continuous dark baby blue backlighting that is free of blemishes and a needle fine trigger that is reported to be ten times more responsive than professional audio meters - lightning fast! This concludes the main features of the faceplate.

Across the top of the MHA100 you can’t help but notice the two labelled autoformers for each stereo channel. This patented technology is rather difficult to explain, however the output audio signal via the single ¼” front pannel output is tapped straight from the single wound autoformer where the user has the ability to select between three output impedance's to match the sensitivity of the headphones being used. The three impedance ranges appear sensible for current headphone specifications where the selectable ranges are; 8Ω - 40Ω’s, 40Ω - 150Ω’s, and finally 150Ω - 600Ω’s. With the ability to select the optimal impedance range for the headphones via the simple click through menu system, the user is able to match the output power to the efficiency of the headphones being used, thus tailoring the system for optimal sensitivity and dynamic range. This is a feature missing from many headphone amplifiers, although McIntosh have gone to significant effort to implement this feature and it can make a huge difference to the accuracy of the soundstage. On a slightly different note, the MHA100 has a significant amount of output power that it is fully able to drive thirsty cans including tricky planar magnetic headphones.

Having previously mentioned the trade marked HXD™ function, McIntosh have chosen to not complicate matters by simply offering a single On/Off selector for the Headphone Crossfeed Director. Essentially labelled as ‘Crossfeed' by many other premium Hi-Fi brands, Crossfeed is an artificial method of processing audio in a way that opens up the soundstage so that, when engaged, the listener can experience similar three dimensional characteristics to what would normally be associated with listening to a pair of loudspeakers. When this function is combined with the impedance selector the user has the ability to experience optimal audio reproduction in two different environments with only one pair of headphones. This technology is remarkable when compared to other brands efforts and completely allows the music to take on a new life. Usually Crossfeed is a matter of taste, however I have never found myself enjoying it both on and off - McIntosh’s patented take is stunning!

McIntosh MHA100 BackAt the rear of the device you immediately notice that this is not just a headphone amplifier, this is a mini integrated system if the user so chooses to use it in this way. Most noticeable is the large passive finned heatsink which clearly harbours the 50w per channel amplifier circuitry deeper into the device, and either side are two 24ct gold plated binding posts to allow for biamplification with or without banana plugs. Below the amplification circuit is where a whole host of analogue and digital inputs and outputs can be found. First, on the far left, is the IEC input which has a significant amount of room surrounding it to allow for custom IEC’s that feature oversized connectors. To the top of this is a single fuse porthole which is easily user accessible to replace with premium fuses such as the Synergistic Research SR-20’s. Just to the right is the power control input and outputs which allows the user to connect their McIntosh system together and easily power on a stack of separates for convenience. Again, slightly further over, is the ‘Digital Audio Inputs’ sector. The first thing that we notice is that the MHA100 has a USB Type B input. Miraculously McIntosh designed the MHA100 with an asynchronous digital to analogue converter that actually rivals many of the current leading FPGA based DAC’s. The DAC built right into the MHA100 has very impressive specifications and is able to go up to a bit rate of 32 and sampling rates up to 192kHz. Currently the chip implementation is unknown, however its capabilities are outstanding; as we shall come to later on. Again, it is nice to see that there is good room around the USB connector and the fact that it is a Type B input means that it is standardised and enables the user to choose as to what advanced ‘boutique’ USB cables they would like to precision transfer their digital data, and just to the side of this sits the ADAT (commonly known as ‘Optical’) connector, Coaxial connector, and AES/EBU Neutrik banded XLR inputs. McIntosh have included more digital inputs than you can shake a stick at - you could literally not ask for anything else, but with the posts not being recessed on the Coaxial connector you will not have any issues with tight fitting premium cables. In terms of connectivity the MHA100 is without flaw and each of the terminals are well seated to the chassis and the general layout is well thought through. However, it would have been nice to see a fully balanced four pin output on the front panel. Obviously this would impact the clean chic appearance of the faceplate, but currently the MHA100 leaves some balanced headphone users frustrated.

In terms of usability the MHA100 is a device that doesn’t overcomplicate the practice of delivering impressive sound to the user within seconds. The MHA100 is super user friendly and intuitive whilst offering a whole host of options that would typically be seen on a device labeled as an integrated system. With a rock solid build quality the MHA100 will undoubtedly last many years. However, whilst some may consider that placing a DAC in such a legacy system is a slightly risky move due to the inevitable technological development of DAC chip design over the coming years, I have no doubt in my mind that the prestige digital to analogue capabilities of the MHA100 will continue to impress in the long term.

Processing Technology:

In order to process this review we have used an array of technology including; Beyerdynamic T90, Fostex TH900, Grado RS325e, Beyerdynamic DT250, Audio Technica ATH-M50, Computer Audio Design USB cable, The Chord Company Signature Tuned ARAY RCA, Chord Electronics Hugo, Lynx Studio Technologies Hilo D2A/A2D Converter System, ARCAM irDAC, Audient iD22, Benchmark Media DAC1D, Sonic Studio Amarra, and MacBook Air 2013.

As the MHA100 is first and foremost marketed as a headphone amplifier the following text specifically focusses on this area.

Sound Quality:

Before any detailed analysis is embarked upon, I cannot help but set the tone of the following descriptive by confidently stating that the MHA100 is one of the most sophisticated headphone amplifiers currently in existence. The MHA100 follows a familiar royal suit of being so open and so effortlessly detailed that the overall presentation is inherently natural regardless of the caliber of headphones being used. This is, of course, a very personal experience that the MHA100 seems to warmly nail without genre prejudice or any distinguishable distortion that would otherwise dull the experience. Noting the word ‘experience’, the MHA100 is not a cold amp, it is a second to none headphone amplifier that provides a translucent window into the life and soul of the music being consumed where the listener intimately feels the music to the extent that they can pseudo place themselves amongst the instrumentation. Now, there are very few devices on the market that can do that - this is audiophile nirvana.

The MHA100 has vibe, it categorically has life because with the MHA100, McIntosh have built a well timed unit that has a superior, apparently adaptable, transient attack and decay that, for some reason, feels the groove perfectly and presents every genre and every note played with utter perfection. For example, the MHA100 never feels too slow when a powerful bass line dominates the lower frequencies that becomes invaded, every so often, by a percussive transient note attack. Again, even the smallest of micro-details and their soft transient presences are identifiable regardless of whether the stage is brimming with complex instrumentation. To put it into perspective this is like being in a silent hall with a pin being dropped ten meters away and every nuance of its bounce being easily identifiable. This is a highly desirable trait that is exceptionally difficult to master, yet this remarkable headphone amplifier strangely feels as if it has automatically sensed the forthcoming waveform and calibrated itself in the most organic way. Because of this the music is music and the MHA100 is dynamically rich enough to invoke all of the natural emotions experienced; particularly with acoustic instrumentation, aka. Classical.

Briefly coming back to the noise floor itself, I have to say that the MHA100 exhibits such a low noise floor that it is practically impossible to hear at any volume. I strongly believe that this quality plays a part alongside the ultra low harmonic distortion characteristics of the autoformers to enable the MHA100 to have excellent staging that extends past the traditional realms of stereo recordings and the limited capabilities of the headphones themselves. Even without the Headphone Crossfeed Director (HXD™) being active, headphone listening with the MHA100 is natural to the extent that the brain and ears calculate the sound to be coming from further afield, that the sound is not stuck to the side of ones head, and that the panning is naturally presented similar to a concert experience. When the Headphone Crossfeed Director (HXD™) is active the soundstage is increased in width and depth to create a more Hi-Fi sounding experience with a slightly thinner sound, although it is still rich in dynamic range and bass presentation. Unlike some other brands, McIntosh’s take, with regards to the Crossfeed, appears to be more refined because the output retains the general feel of production and maintains a symbiotic relationship with the groove to produce a slightly expanded stadium-esque feel to the original timbre of the record. Thankfully the coherence in this mode is accurately judged and never takes the music into sloppy territory, quite the opposite.

The audible bandwidth of the MHA100 is vast, however with a reported frequency response of 20Hz to 20kHz it would appear that McIntosh have underrated their device due to the fact that the upper and lower frequency boundaries appear to extend well. The sub-bass has a brilliant focus that knits strongly with lower midrange frequencies in a way that never seems to muddy the articulation of supporting rhythmic instruments. In fact it has a pleasant, yet powerful, deep clean punch (when required) and a marvellous airy quality that allows you to hear feel the environment around the instruments. Moving on to the midrange, the MHA100 exhibits silky rich tonal qualities to create a rather unique transparent character that compliments and balances well with the lower frequencies. This balance is well judged and bleeds into the upper frequency where the range is completed. The MHA100 has a detailed neutral treble that is fluid and does an excellent job of opening the music up and delivering bags of character. There is no evidence of crunchy piercing harmonics being added to the original signal, in fact every note or nuance is luxurious and pin sharp. The word best used to describe the sonic signature in general is ‘perfect’, there is literally nothing that I can fault across this entire area. It is for this reason that I implore you to experience the MHA100 with your own ears, this is an experience to behold.

Review Conclusion:

Legendary in design and performance, McIntosh component systems are often iconised by a pair of soft blue glowing analogue VU meters, a lime green logo, a glass faceplate, only finest in-house custom components, and a minimum year long painstaking engineering process to create an unparalleled royalty listening experience that is built to a standard, not a price. Every McIntosh system is, unequivocally, an astonishing work of art held in the highest order the world over, and the MHA100 is no exception to the rule. The sound quality is astonishing and presents an intimate listening experience that is nigh on impossible to beat. The MHA100 is a feature packed unit that is hard to fault and, for this reason, the MHA100 is awarded with five of our finest stars and our outstanding award badge.

Edd Harris

Edd Harris - 26th October 2014

US RRP: $4500.00 | UK RRP: £4995.00

Editors Rating:

Five Star Review
McIntosh MHA100 Headphone Amplifier Review
5/5 stars
McIntosh MHA100 Review: The MHA100 is perhaps the finest headphone amplifier currently in production. With an exceptional build quality and class leading performance McIntosh Labs have excelled themselves. This headphone amp has already become a legend in our books.
Outstanding Award - The Pro Audio Web Blog