Pros: Great price, optical out, dual headphone jacks, small size (almost portable)
Cons: No optical in
I just received my Audinst amp yesterday, and only have about 15 hours on it so far, so this is a review based on my early impressions..
This is my first serious, dedicated amp/DAC combo that I bought to power my Beyerdynamic DT 990 PRO (250 Ohm) as the FIIO E5 I had just wasn't cutting it. I'll be updating this review as the amp burns in, but I can say that at the moment, I am liking how the amp pairs with the DT990.
Review gear: Macbook Pro > USB > Audinst HUD-MX1 > DT990
:: Looks ::
The Audinst is a small, small amp. From the pictures on the Audinst homepage or the internet, one would think it's bigger than it is, but it's really not much bigger than a Penguin paperback and quite light. For all that, it's quite solidly built, and all the switches, knobs and jacks feel secure and well made.
The amp can run off either the supplied AC wallwart, or can be powered from your laptop's USB port. There is no power switch on the unit, as it automatically detects whether your computer is on and turns itself on and off accordingly. A nice feature.
:: Sound ::
First off, this amp has plenty of gain, and anything beyond 10.30 -11 on the dial soon becomes deafeningly loud. There is an internal jumper that can be set to increase the gain for 300-600 Ohm headphones, but I can't imagine needing to do so even for higher impedance cans.
Installation and setup on the Macbook Pro is a breeze. First, open Audio MIDI Setup and select the Audinst as audio output. Change the audio settings to output 24bit/96khz if you like. Open up System Preferences and select the Audinst for output and you're in business! (Helpful hint - hold down the Option button and click on the volume icon in the menu bar to switch outputs without having to open System Preferences)
Note that iTunes automatically selects the Audinst for output, but for other programs like VLC, make sure the amp is plugged in and selected for output *before* playing music or movies. Took me a few minutes to troubleshoot that last night :)
So how does it sound? I selected a few songs from different genres that I used to test out various headphones before picking the DT990, so I knew what they sounded like through the E5, or straight from the MBP's headphone jack. All songs are 320 kbps MP3 or lossless FLAC.
Martha Argerich - Chopin: Scherzo #3 In C Sharp Minor, Op. 39 - Presto Con Fuoco (Debut Recital)
This recording showcases Argerich's dynamic (some would say rough, but not I!) interpretation of Chopin, and this track runs the gamut from soft and intricate almost whispered chords, to symphonically brash peaks. The Audinst renders the rather intimate recording quite nicely, and I can pick up some overtones that I didn't catch before. The soundstage is not as large as it could be, but it's more a case of being in the second or third row (or in the back of the studio for the Scherzo).
Magnetic Man - Anthemic (Magnetic Man)
Opening with a scratchy, fuzzy, white-noisey beat before the typical dubstep-y bass drop wibble-wobble, I use this track to test for lower-end bass, and the Audinst delivers here. With the DT990's already bass-heavy presentation, the Audinst gives a cleaner, firmer bass whump to the opening kickdrum, and really opens up the lower-end to let the DT990's reach down for bass that I imagine should be vibrating in my chest. Definite improvement to the sound here.
Moto boy - Blue Motorbike (Moto boy)
I chose this track because by un-amped DT990's sounded quite bright (almost shrill) reproducing the higher treble of the metal guitar Oskar Humlebo uses here. Happily, the Audinst tames the ear-piercing treble without rolling it off too much, and you can enjoy the twee, Twin-Peaksy warble of Oskar's unique voice without wincing as he reaches for those upper chords.
Music from the homeland:
I listen to a lot of African music, which employs a lot of instruments and vocal styles not heard much in Western music, so I'm always keen to hear how well an amp can reproduce the sound given the varying qualities of the source material.
Khaira Arby - Goumou (Timbuktu Taarab)
Another track that the unamped DT990s struggled with. Again the Audinst stepped up to the plate delivering better instrument separation, and letting Khaira Arby's voice ring out clearly without making it sound like she's reaching (and struggling) for the notes.
Toumani Diabate - Si Naani (Mande Variations)
Just gorgeous, shimmering, and a treat to listen to.
Koffi Olomide - Victoire (Attentat)
One of my transfers from cassette tape to MP3, and it sounds like it. Well, I wasn't expecting the Audinst to make this sound like a clean master by any means, but it does it's best to make it listenable with revealing headphones.
:: Summary ::
The Audinst is a reasonably priced, and quite capable DAC/amp combo that should suit anyone just starting out in high. With the ability to roll opamps and to use this little box as a DAC with better amps (I'd like to try it with the Matrix M-Stage someday) I think this is a great buy at less than $200.