Review: McIntosh MHA100 (headphone amplifier with USB DAC)

The McIntosh MHA100 is definitely the most singular headphone amplifier we’ve ever had the pleasure of testing. The US brand, which clearly does things differently from its competitors, and not in half measures, with its MHA100, doesn’t just simply limit itself to headphone amplification but gives the listener the opportunity to run a pair of speakers thanks to an output stage capable of delivering 2×50 Watts at 8 Ohms. In addition, it incorporates a digital to analog converter with USB as well as optical and coaxial inputs which are compatible with PCM streams up to 32 bits and 192 kHz. Both computers and optical sources can thus be connected. Before we talk about the technical aspects of the McIntosh MHA100, here’s a brief word on the design, which is both vintage and modern and combines VU meters with a blue LED backlight, aluminium potentiometers and a toughened glass front panel.

Patented technology

The specific feature of this headphone amplifier is the presence of two autotransformers, technology which is specific to McIntosh and which allows the amplifier to adapt to the impedance of the speakers used. For this amplifier, this technology only applies to the headphones output with, consequently, an adjustable adaptation to the connected headphones’ impedance (which can be selected by the user). What are the advantages? Fluidity and sound aesthetics are maintained at all times, regardless of the connected headphones’ impedance curve. All the components are, furthermore, manufactured in the USA in accordance with strict specifications.

Detailed headphone listening

We listened to the McIntosh MHA100 with several sources ? a computer firstly, using a USB ASIO connection and the supplied cable, then with a PopCorn Hour A410 multimedia player via the optical Toslink input and an Audioquest Vodka cable. Listening with HiFiMAN HE-560 and HiFIMAN HE-500 headphones turned out to be exceptional. Like any major amplifier, we often judge its performance in the bass range. Using the MHA100, the bass has a rare density, which is dramatic in its variations without being flamboyant. Breathing is constant, reversing initial expectations of listeners, who are used to a less subtle, even drastic delivery for certain types of music. This range doesn’t overshadow the other ranges as the medium is very detailed and perfectly integrated with voices to the fore. The mixing of sound levels is soft and dynamic. There isn’t a hint of harshness in the high frequencies. Strings and cymbals are constantly free-flowing.

To put it simply, we’re really listening to music and that is patently obvious.

Finally, with a couple of Watts delivered over an impedance range between 8 and 600 Ohms, the McIntosh MHA100 can power any set of headphones.

Users can select gain adjustment in accordance with the impedance of their headphones. In the 8-40 Ohms mode, the maximum power is 250 mW.

How about speakers?

Therein lies the surprise. Although no autotransformer is solely dedicated to speaker amplification, performances are, nevertheless, excellent with 2×50 Watts at 8 Ohms for an extremely low distortion rate (0.005 % at full power!). When listening, that relates to the capacity of dissecting sound levels while maintaining overall natural consistency. With a pair of Klipsch RF-7 MK2, we delight in the home cinema atmosphere just as much as if we were listening to music. With B&W CM6 S2 or Sonus Faber Venere 2.0, we benefit from an intimate but well structured sound with guaranteed listening pleasure.

Listening impressions

Handel: Music for Queen Caroline, I – The King shall rejoice, William Christie (FLAC 16/44)
The analytical capacity of the amplifier and its DAC are impressive. Listened to with conventional equipment, this track would just simply be a rough patchwork of instruments, whereas with the MHA100, each instrument comes alive. The fortissimo remain under control. Can there be any better?

Chanson sur ma drôle de vie, Véronique Sanson (FLAC 16/44)
It’s not the most impressive of sound takes but a good amplifier should be able to extract the heart and soul from each track. We revel in the sound of the piano and Sanson’s voice is full of life. After re-discovering this song, we now understand why it was such a success.

You’re the One that I Want (Live, London 2014) – Angus & Julia Stone (FLAC 16/44)
A really good sound take which allows you to explore the atmosphere of the concert venue. The strings and bass drum are magnificent. There is incredible depth even when the audio message becomes more complex.

Crache ton venin (live 1980) – Téléphone (FLAC 16/44)
We didn’t think twice about testing the MHA100 with ?rough tracks? like this live track by Téléphone, which is extremely difficult to deliver. An old-style sound take with lots of details in the lower-medium and upper-bass ranges but less in the extreme bass and treble. This is a delight on a McIntosh MHA100 and the Klipsch RF-7 bring just the right amount of articulation.

Titanic, VO DTS HD MA > PCM stereo 24/96
This creates an immersive atmosphere during the Irish party scene in third class. Drums are delivered with an uncommon richness of tone. We can easily hear the biniou pipe player breathing and the violin strings, despite the density of the sound stage. It goes down very low during Never an absolution with lots of impact. The Klipsch RF-7 give it their all.

Pacific Rim, VO DTS HD MA > PCM stereo 24/96
Once again, the MHA100 surprises us, as it hasn’t apparently been optimised to work with speakers. Ramin Djawadi’s thunderous soundtrack puts many amplifiers to the test, without necessarily boosting the volume. Once again, the infra-bass waves are mastered and don’t overshadow the other ranges. Dialogue remains clear and well integrated. To really appreciate the power of the MHA100, you should listen to the opening scene where listeners are literally transported to the heart of the storm. The Klipsch RF-7 MK2 speakers are always kept busy while the B&W CM6 S2, which we also used, surprised us with their precision in the upper-bass range, despite their dimensions which do not necessarily lend themselves to such a range.

Conclusion

Although McIntosh presents the MHA100 as a headphone amplifier, it is undoubtedly much more than that. Only the headphones output is fitted with autotransformers but the fact that there is an excellent DAC and speaker output and that you can use it like a stereo pre-amp make the MHA100 an absolute gem of an amplifier.