Audinst HUD-MX1 - Review
The HUD-MX1 is Audinst's first ever DAC and headphone amplifier but on the 17th of this month they will release a new model, called the 'HUD-Mini', which features a Burr-Brown PCM1791a DAC and some impressive specs. Until then, the MX1 remains the Korean company's only option to buy. It may not be quite so mini, but it's still perfectly portable and although it has a 15v adaptor it will run from USB power perfectly well. At £115 it costs a little more than most other devices using the rather common Wolfson WM8740 DAC, so the big question - Is the MX1's audio quality worth the money alone?
Sound
The MX1 displays a perfectly clean sound, with a signature probably more neutral than any of the other DAC/amps in this group test. The biggest reason for this was that the bass felt more lean than most, but still plenty weighty enough to enjoy any House or Dubstep with great presence. In fact, almost anything with heavy bass sounded great on the MX1 because of the slight tightening up of the lower frequencies and additional detail. It's not until much pricier models that I find you can enjoy both more bass and better detail together, and at this level the MX1 feels like a great balance between the two. This won't suit everyone of course - if you have less bass heavy headphones and enjoy the push they get from a bass heavy amp then you might find it all a bit too lacking and/or sharp, but I sense that the majority of people will prefer it.
The midrange is great! Certainly unaffected by the bass, since it's less plump here anyway, but it's very clear and almost feels forward with a real vibrancy. Vocals are presented in an enjoyably detailed, deep and slightly smooth way. The treble is quite bright but fairly well controlled and with a nice feeling of sparkle. There is a great sense of crispness and texture detail without feeling too shrill or giving much sibilance.
The soundstage presentation here is really quite stunning for such a reasonably priced unit. With plenty of depth and separation without feeling artificial. This of course has to go hand in hand with the capabilities of your headphones. Generally speaking, it's worth noting that these devices won't fix headphones with a poor soundstage and make larger differences where the effect is already quite good. A good open back headphone will do this best, but even though I was mostly stuck on fairly capable closed back headphones, like the VModa M80 and Denon AH-D7000, I had a very enjoyable presentation.
Comparisons
Although the MX1 shares the same DAC as the Fiio E17, it's not much of a threat to the sound quality of the Audinst. Unlike the E17, the MX1 has no battery and no ability to use the amplifier on its own at all. This is a bit of a shame considering it can be powered by a 15v adaptor, but at this price you can't complain too much with such an impressive sound quality. I preferred the bass presentation of the MX1, being less plump and noticeably better textured. The midrange and soundstage were also a big improvement for me over the Fiio E17. I've made the Fiio sound poor now and that's unfair because it's not. It's just that the Audinst feels not only better, but better value, even compared to the brilliant little Fiio. Of course some of the Fiio's desirability will come down to features but purely on audio quality alone the MX1 wins for me.
Compared to the HRT Headstreamer some of the audio quality felt close, but in general the Audinst is just too good. Again, not only did the MX1 feel better value, but it's sound quality just felt better overall, despite being cheaper. The MX1's bass presentation was less bloated, the detail and soundstage was a touch nicer, but mostly the midrange was more forward without being overly so. Feature wise, the HRT loses here too. It has no power options, no alternative analogue or digital output, no large headphone connection (6.35mm), no physical volume control and the front USB port felt rather awkward by comparison (really should be on the back). I'm afraid that the American Headstreamer, as capable as it is, is rather crushed by the sheer value, impressive features and sound quality of this Korean monster!
Features
The MX1 supports up to 24bit 96khz through it's USB connection. Like most DACs with this specification, it needs no drivers. As long as you restart your software, it works instantly. This easy plug-and-play feature is a fairly common one among USB DACs, but despite the power options of the MX1, it gave me the least amount of issues. It just works and it's very reliable.
As you can see by the front panel of the MX1, it includes both 3.5mm (1/8") and 6.35mm (1/4") headphone jacks. I love this feature because I have headphones with both types of connection. No messing around with adaptors, everything connects without fuss. I think Audinst deserve big praise for this, as so few amps have this, especially at this price level.
Around the back is the USB input, of course. We're blessed by a full sized USB-B connector, which is a little less common connection for portable DACs, but it's nicer to deal with as it can be more easily located from looking at the front. Analogue RCA connections are a nice addition if you want to use a better headphone amp or a full sized amp with speakers. The output here is controlled via the volume dial, so is a useful desktop solution if you have active speakers without volume control. There is a switch on the front of the unit to change the output from the headphone sockets to the RCA. The last connection here is an optical S/PDIF output which will pass through the digital signal to another DAC, apparently it will even pass through 5.1 surround, although I have not tried this.
The MX1 will run solely from the power through the USB connection (both the DAC and the amplifier) but if you prefer it can take power from the included adaptor which plugs in to the wall and supplies a more healthy 15v (compared to 5v in the USB). This is a nice feature and a rather rare, flexible option. If you have more demanding headphones, there is an option to increase the gain, unfortunately it requires taking the unit apart and changing a jumper directly on the circuit board. It's not the easiest thing to do, but at least it is possible. For most headphones this will not be necessary since there is plenty of power on tap here, but perhaps this is where the included power adaptor comes in to its own..
Build
The build quality of the MX1 feels and looks good. It seems well put together, nothing moves around or rattles, and the chassis feels strong enough to take some knocks. I really like physical volume dials, so the MX1 gets a few more points from me here. Although the volume dial is plastic, the low weight and slightly tough turn makes it feel very strong and precisely controlled.
The packaging for the MX1 is very nice (polar opposite of iBasso) and inside the box is everything you need. Of course, you get a USB cable (the less usual, non-mini type) but you also get rubber feet for the unit which sit it nicely on a desk. I was also surprised that they included a power supply since you don't really need it, but even more shocked to see phono cables (RCA) in the box since that's something you are usually expected to buy yourself. I was quite shocked at this for the price, it feels like Audinst really want to go above and beyond to bring satisfaction to their customers.
Summary
I really like the consideration that has gone into the HUD-MX1 as a whole, it feels like a very well-rounded product. The great connections, nice build quality, reliability, ease of use, power options, included adaptor / phono cables and a lovely volume dial are great, but it's still the audio quality impresses the most. The neutral signature, decently textured bass, expansive soundstage and commendable detail is easily worth the asking price alone.
Audinst's next DAC/amp (HUD-Mini) sounds very interesting on paper, especially given it's cheaper price, but it's a rather different animal and until I get a chance to review it the MX1 is one of the best value units that I have heard and gets a highly recommended from me.
Posted June 2012
by Edd