Pros: It's like an E9 in your pocket, with lower output impedance, a crossfade feature, a boost to counter sub-bass roll off, for just $30 more!
Cons: Slim, but not the easiest to use from within jeans pockets. Bass boost is subtle. Vs cheaper amps, small improvement for easy-to-drive headphones
Here's my long-delayed E12 review on an early pre-order model.
I waited to get a good feel with many songs before posting this, and a good feel for how the amp affects the sound presentation. I tested it with my standard playlist to get a reference point of view, but you'll see references to other songs sprinkled throughout the review that I think are relevant for illustration purposes. This is mostly a subjective review because I have few tools but my own ears, but I hope I provide enough data for others to make their own conclusions.
I tested mostly with my AKG Q701 headphones, because they are my primary headphones and notorious for their performance variability with different amps, and I also tested with my Etymotic ER-6i, because they have a remarkably flat frequency response through most of the range.
Extremely nice. Think "Apple Unibody Macbook Pro" nice. The external shell is made up of 3 main parts: a solid, black, matte finish brushed metal tube, and two matching end caps. The only visible screws are two on the bottom piece. The seams between the end caps and main section have less than a hairline gap, evenly fit all the way around. Ports, switches, and the volume knob all have great looking chrome accents: the bass switch even has many concentric rings on the face of it, so you get that "CD" reflection shape on it. The volume knob is small but with a great volcanic grip, very stiffly dampened so you won't change volume in the pocket and small volume adjustments are easy. The "Power On" and "battery" LEDs are separate, the "battery" LED blinks when the battery starts to run low and "breathes" while charging, varying speed according to how much charging power the Mont Blanc is receiving.
Here is a video I took with my iPad of the E12 right after unboxing
Feiao "Depend on the test of the engineer sample, the output power @32 ohms headphones is about 1.3w to 1.4w, and @16 ohms headphones is about 900mW, so I believe it can drive almost all hard to drive headphone except some " monster " headphone like the AKG K1000."
Playing on 0 dB gain setting, listening volume for me is at about 11 O'clock with my AKG Q701, 10 O'Clock with my Audio Technica AD700, and with my Etymotic ER-6i IEMs (which I am listening to as I write this), is just a bit above 9 O'clock position on the volume dial. Off position is about 6:30-7 O'Clock, and the amp turns on at about 7 O'Clock. Max is at 5 O'Clock. Happily, I cannot humanly detect a channel imbalance at listening volume with my ER-6i.
The amp can be used while charging, though your typical mains power will introduce a little background noise. It charges with a USB port, I think a Micro "A," conveniently the same as my phone, drawing tablet, and many other devices, but unfortunately different from the Mini usb port used in the FiiO E11. Full charging varies with how much voltage is supplied (i.e. faster from a wall socket than a computer), but should be done in 4 hours or less.
>0.5Ω, very good and suitable for basically any headphone.
124x65.5x14.5 (mm). 159g weight.
Portable, but a full-sized portable. It can slip into a pants pocket, but you might feel uncomfortable with a larger music player strapped to it. It's a smidge thinner than the E17, but a cm wider and 3 cm longer. Think of it as about the size of a large smartphone (My mom's Samsung Android is bigger). FiiO quotes >12 hours for the battery, in typical use I go days between charging (I use this to amp my gaming setup in addition to listening to music). The battery LED blinks when the battery is low, but I haven't noticed any degradation of audio quality right up until the moment the power goes dead.
There is a slight issue of organizing the connector cable between amp and PMP. I personally think two straight plugs is the answer, with the included right-angle plug male-to-male cable cramping up the "top" plate and sticking out a bit, perhaps making it tough to have strapped to a PMP, in a pocket, and in use at the same time. Still more portable than a cassette or CD player though!
Subjective Sound opinion
Dead honest, with almost no additional coloration over what the headphones already have (at least as these human ears can hear). My tube amp is a bit more revealing and brings your attention to micro detail and texture more, but… that might be over emphasizing, I can still hear that same detail (for example the backing sub-bass right now in Bjork's "All is Full of Love"), it's just perhaps more integrated with the rest of the sound character and thus more "musical" than "analytical." Me gusta, definitely belongs among high-tier amps.
Kick and Decay:
There is a nice tail off of reverb in classical songs (and obvious with the Radiohead - Lotus Flower song I'm listening to right now, sounds like it's in an empty opera hall instead of the warehouse I'm conditioned to expecting from the music video), but at the same time everything feels fast so I get a little of that "adrenaline feeling" where I can hear everything so clearly that time seems to slow down.
Since I got my PPU E12 on January 17, I noticed an increase in impact/kick to the urgency of notes with my Q701, but right now Van Morrison's "Oh the Warm Feeling" playing over my ER-6i sounds just "right." The Q701 varies the most with different amps, but overall with the Mont Blanc, I find the sound exciting and involving.
Soundstage (depth + width):
The presentation of soundstage seems to be a very good match with the Q701. I play video games with THX TruStudio Pro surround processing, and straight out of the USB sound card the soundstage seemed oval shaped, wider and not as deep, but adding the E12 rounded out the sound much more evenly circular. It does seem to stretch out and have more "air" than my iPod's headphone out. Not as emphasized as with my tube amp, but that amp may be "overemphasizing."
EMI & Hiss:
Mostly negligible with the Q701, hiss is inaudible until I switch to high gain mode (so quiet that the first time the E12 battery ran out, I thought my iPod had died and the amp was still on). With the 16 ohm, very sensitive ER-6i, I could hear hiss on low gain at around 12 O'clock on the volume dial… but that's way too loud for me to listen. I can't hear any noise when I call someone (with my basic phone…), even with my Ety's.
There is a switch to enable a crossfeed (subtle but nice with hard panned songs), and a unique bass boost.
The bass-boost is apparently under contention right now. Currently, the boost isn't about skewing the balance of frequencies towards bass... It's completely focused on the sub-bass region, reaching down to the limits of human hearing and mostly just making "atmospheric bass" more authoritative by 4 dB. It's very clean, too. Others have asked for a stronger boost that affects the mid-bass area. I like the E12's boost the way it is now, and here's why... It's unique. Atmospheric bass is a new thing to me (when I started following this thread last year, my main headphone was the AD700), and I don't know of any other amp (the E11 is close) with a hardware boost that focuses enirely on sub-bass, leaving the rest of the frequencies to ascribe to the "wire with gain" philosophy. It's a boost I feel I can leave on with almost any song or genre. With the bass boost of the E5 I also have, the boost was stronger and changes the tonal balance, but it introduced a distortion as well, and usually hurt songs with added grain instead of helping. What do you think?
There is also a relay circuit that causes a delay from the moment you switch on the amp to when it "connects" the headphone jack to power. This avoids the power on "POP!" and protects your headphone (and ears), a feature very common in speaker amps.
Lastly, when I first got the amp, I was honestly a little disappointed. It sounded technically very accurate, but there was a sort of "coldness" to the sound and I wasn't feeling very emotionally involved. Like the amp was holding back somehow. After 3 hours, I took a break and got some coffee, came back to the amp, and slowly (as I was typing to someone about it, in fact) "Q701's are digging in deeper and sounding much nicer... Ooh, right as I was typing that, the last track of "The Suburbs" was almost finished and softly hit me with a really low bass note, gave me a chill!" As I listen now, I just melted a bit at the intro to Muse's "Resistance" from the album of the same name. Back when I first heard the E12's "musical side" I put it down as my ears adjusting to the sound signature, but someone else in the E12 thread had a similar experience, and another, then JamesFiiO stated that the WIMA capacitor actually burns in over time. So, I guess now I'm a believer, lol.
Philosophy of Use:
So who is the E12 Mont Blanc for?
Honestly, I think it's NOT for people who only own "made for iPod" headphones, you will hear very little improvement for your money, and something like a FiiO E5 or E11 will be more portable. If you are a bass head and you like the signature of your headphone, this E12 will drive it cleanly and with authority and perhaps with tighter detail, BUT the bass boost is subtle and won't transform a balanced headphone into a sub-monster, in the latter case another amp with more boost might be better for you. Also, someone with a hard to drive headphone may look at said high-impedance, power-hungry Studio Monitoring headphone and ask themselves, "Why do I need a portable amp for these?"
HOWEVER! I think the E12 is handy compared to a desktop amplifier of equal (or lesser) output power for transporting to work or packing for a vacation. The E12 is also handy if you have a lot of "listening spots" around the home, where you connect to different sources (for me: Desktop computer, Xbox, Laptop, iPod/iPad) or if you just want to listen while lying in bed. Finally, the E12 may be the only all-around amp needed, for current or future headphones (except for something like a STAX), and that, to me, represents real value.