I finally had time last night to install my MHA100 in my system. It is place in my bedroom system which is a combination of speakers and headphones system. The two sources are a Mark Levinson 37 CD transport and a Mac Mini Server with 16 Gb in RAM, 120 Gb SSD for the software and 1T HD for the music files with a 3T external HD for TimeMachine. I am also using the iUSB and iPurifier. All de USB cables are WireWorld Platinum. Both sources feed a Bricasti M1 DAC with the latest upgrades. I am splitting both RCA and XLR signal out of the M1. The RCA output is feeding the Woo WA5-LE and the Stax SRM-727 II (that I am hopping to sell soon to buy the RSA A10 Thunderbolt). The XLR output is feeding the MHA100 and my Threshold T2 preamp highly modified by Jon Soderberg (which I might sell if I like the A10 synergy as preamp with the Threshold S550e amp). The T2 feeds a Threshold S550e (250 watts/ch and 30-130 amps per channel). The speakers are B&W 803N on Sound Anchor bases and a REL Stadium III subwoofer. All interconnects are WireWorld Eclipse 6, Speaker cables are WireWorld Eclipse 6 bi-wired and all power cords are either WireWorld Electra and Silver Electra on the MHA100 and S550e. The system is fed by two dedicated 20 amp lines. One for the amps and one for all the sources.
So far I have listened to the PM-1, Alpha Dog, W3000ANV and the HE-6 out of the speaker tabs. I am sure you already got the hint that I am not using the MHA100 internal DAC and I have no intentions of doing it because I already have a high performance DAC in the Bricasti that I love.
My initial impressions on my own MHA100 confirms the ones I got at the dealer when I auditioned it. First of all the looks of this amplifier are the best of all headphones amplifiers I have seen based on my taste of course. If you like the classic McIntosh look then you are in for a real treat. It looks like a "mini me" of any of the stereo speakers amp with meters . The construction is typical McIntosh... very solid and excellent fit and finish with a hefty weight to it.
Its sound is very clean with a very dark background and no identifiable floor noise. In gaps between songs there is no noise or anything else just totally quiet. The sound is very clean and dynamic. The level of detail is very nice but without getting into the analytic area it is actually very musical. Its bass is deep, fast and controlled. The treble is very detailed with a nice level of sharpness without being piercing and fatiguing and the mid rage is so very sweet and full of body. The overall presentation is very balanced and dynamic basically the same sound signature of my MC601 monoblocks in my living room system (I love their sound so much. That was the main reason to motivated me to audition the MHA100 in the first place). So far it has performed excellent with the headphones I have tired so far. I have left to try the HD800 which I know it works great because when I auditioned it at the dealer if used them and that was the time I have heard the HD800 sounding the best (even better than with my WA5-LE. The other ones are the T1 (which I will sell soon. The have the zeus cable) and a highly modified Denon D2000 that are basically even better than the D5000.
The only thing that I do not like in the amp is the effect of their crossfeed processing that they call HXD. When it is engaged the sound is presented more in front of you like when you are listening to speaker BUT (big BUT) at the cost of soundstage presentation and tone. The soundstage really collapses getting really narrow and the tone gets quite darker loosing a lot of the transparency of the amplifier. Unless McIntosh change something in their software to improve this effect and makes the update available to all users I don't see using this HXD circuit ever.
Since I started in the HeadFi world I have own many different SS (and hybrid) amplifiers always trying to upgrade. My first amplifier was the CIA amp with the matching external power supply and from there I have had the Heed Canamp, Stello HP100, Rudistor RPX-33, RP-07 Lite, Headamp GS-1, Rudistor RP010B MkII,V200, Apache and Dark Star. I have also audition the LF, LG, Master 9 and Luxman P1. From all that list I place the MHA100 at the top based on my taste of looks, build and sound. Is it expensive, heck yes but at the range of the RP010B MkII, Dark Star, EAR, Cavalli, Eddie Current and others (and BTW neither of those have a DAC so comparing the MHA100 just as amplifier is fair) and you get behind you the tradition and legacy of a company that has been in the Hi-Fi industry for over 50 years with a proven record and in addition to the high resale value the McIntosh equipment traditionally keep so to me that is worth something too.
These are just my impressions and opinions based on my taste and preferences. I will post pictures later this weekend.