Our friends at the FiiO headphone- and mobile player paraphernalia company sent me their newest oeuvre for reviewing – the FiiO E7, a portable headphone amplifier and USB sound adapter (also often incorrectly called pars-pro-toto ‘DAC’, as the cool people like to refer to sound interfaces), successor of the popular E3 and E5. Unlike some other Chinese manufacturers that cater to an ‘audiophile’ demographic, FiiO managed so far to release products that are of quite high build quality and having good performance while still keeping a fair price. To put it bluntly – in my opinion FiiO doesn’t rip their customers off unlike some other manufacturers, and the E7 is yet another case in point. Despite the E7 being the least inexpensive FiiO product so far, the not so high asking price of around $80 gets one a quite nifty and versatile audio toy.
- Output power: 150mW into 16 Ohm, 16mW into 300 Ohm
- SNR: ≥95dB for AUX, ≥100dB for USB
- THD: <0.009% (10mW, AUX) <0.008% (10mW, USB)
- Frequency response: 10Hz – 100kHz
- Suitable headphone impedances: 16 – 300 Ohm
- Power: 1050mAh Li-Ion battery, rechargeable over USB
- Display: 128x64px two-color OLED
- Dimensions: 96x55x15mm
- Weight: 100g
Design, Build, Specs
In the box comes a ferrite-beaded USB cable, a short and sturdy built 3.5mm-to-3.5mm cable to connect the amp to any MP3 player, a well made soft velour pouch, a rubber band to attach the amp to a larger-sized MP3 player (or to show your love for FiiO on your wrist), and the manual. While the pouch is a nice solution for storing the amp, it’s getting in the way when the amp is used, due to the outputs and inputs on opposite sides of the E7, and the buttons on the left.
The included rubber band raises an important issue: how does one actually use the E7 in a portable setup? Due to the E7 arguably being the first portable amp with a display, it seems the only viable way is to create some Janus-headed monster, with the MP3 player’s display on one side, and the amp’s display on the other side. The bigger issue with that is that the screen of the E7 sticks out a bit from the surrounding metal frame, so it might get scratched rather easily when it lays face-down on a flat surface. A screen protector would definitely be necessary when using the E7 in a portable setup – FiiO might want to think of including one in the box – I’m sure it would save both, the users and the manufacturer, some grief in the long run.
I’ve seen photos of an older prototype of the E7 which had the whole front plate made from glossy plastic. While that certainly looked more modern and appealing, I think it’s good FiiO chose in the end to only make the screen area from plastic and the rest from brushed aluminum – less scratch-able area and less of a smudge magnet that way. The back plate is attached with Torx screws, which adds to the solid appearance of the amp as well; contrary to the run-of-the-mill Phillips screws found in many other amps. The screws act as feet for the E7 so the back plate doesn’t get scratched.
Back to the screen… Said screen is of the OLED variety, the same two-color low-res OLED as found in the Sansa Clip/Clip+ or MobiBlu Cube MP3 players – which is bad for several reasons in this implementation. I will nitpick some more about that in the firmware chapter below, but the main reasons speaking against OLED in this case are visibility in direct sunlight and pixel burn-out when they’re displaying a static image for a long time. I would have preferred FiiO to implement an old-but-reliable (and always legible) monochrome LCD display or a fancy e-ink display in the E7 – both technologies would be much more suitable in this application than an OLED. Of course an e-ink display would be too pricey, but there’s nothing wrong with ye olde tried and proven LCD.
Another important fact to mention is that the E7 didn’t pick up any wireless interference in its vicinity. Unlike many other amps it should be no issue pairing it with a cellphone used as an audio player or a Wifi-enabled PMP/UMPC.
On the top of the E7 we find two 3.5mm headphone jacks (I’ve counted them) and the reset hole (which I never had to use so far). It sure can come in handy having a second output to share music or movie audio with someone, as long as both phones have similar impedance and sensitivity.
On the bottom of the amp there’s the standard mini-USB port that doubles for charging the beefy battery of the E7 and for using the amp as an USB sound adapter (that should work natively on any modern OS without the need for drivers being installed). There’s also the analog 3.5mm input for using the E7 on the go as a portable amp, and in the middle there’s a proprietary dock connector that’s intended to work with an upcoming desktop amp FiiO is planning to release
. This desktop amp will only have analog inputs and the docked E7 will be used as a DAC ‘plug-in’.
The four buttons on the amp’s left side are very well implemented. The grooved surfaces give the aluminum a nice quality feeling. They need a rather firm press to activate. A button lock is implemented via firmware, but the E7 actually wouldn’t need it at all, due to the buttons needing quite a bit of force to register a press.
Volume is controlled via two of these side buttons. The volume control is digital, meaning there’s no potentiometer that might start to crackle and pop over time, and there’s also virtually no channel imbalance at low volume settings, as found on many other amps with analog volume controls. FiiO’s older E5 had a digital volume control as well but it was rather imprecise with only 20 steps – the E7 has a 60 step volume control which should be precise enough for pretty much any application.
Speaking of the four buttons, they’ve got dual functions depending on the status the amp is in. The volume buttons act as up/down selectors in the firmware menus, the menu button acts as enter, the power button acts as escape.
Let’s take a look at the various firmware functions. First menu item is a bass booster in three strengths. Well, ‘strength’ is a bit of an exaggeration – same as on the E3 and E5, the E7’s bass boost is rather subtle and doesn’t make that much of a difference (at least for a basshead like me). Level one boosts the bass by 2.5dB, which is pretty much inaudible, level two boosts by 3.5dB, and lever 3 boosts a not-so-whopping 4.5dB, which is about as much as the bass boost on the older E5 delivers as well. See the RMAA result above for the according graph. Those increments are too closely spaced to really justify having three levels to choose from. I would suggest FiiO to update the firmware to deliver a more useful stepping of the bass boost levels: 0dB, 3dB, 6dB, 9dB would be a good, useful increment, in my opinion – contrary to the too small 0dB, 2.5dB, 3.5dB, 4.5dB steps the firmware currently uses.
The next function in the menu turns USB charging on or off. Turning USB charging off can come in handy when using the E7 as a sound interface with a battery-powered UMPC, tablet PC, or similar media player where the battery shouldn’t be drained by the amp. By the way, the E7’s 1050mAh battery is really beefy – it’s rated at about 80 hours of usage. Honestly, I stopped counting after about 50 hours. Take my word for it – the battery life is great.
Then there’s a sleep timer in the menu – thank you, FiiO! Every amp should have a sleep timer in my opinion. I’m using a Cowon O2 PMP paired with an iBasso T4 amp often for watching videos in bed, and while the O2 turns itself off when I fall asleep, the iBasso runs the whole night and unnecessarily degrades its battery’s lifespan. Well, as nice as it is to have a sleep timer, the implementation in the E7 could do with some work. First, it only goes up to 90 minutes, and second, it increases and decreases in steps of single minutes in the firmware, which is quite tedious to click/scroll through. I’d like to see at least a 120 or even a 240 minute sleep timer in the firmware, and more conveniently spaced increments than single minutes. Something like 10 minute or even quarter hour increments would work much better, and nobody needs an exact-to-the-minute sleep timer anyways.
Next is the key lock function, which is quite unnecessary in my opinion since the buttons on the side of the amp are so sturdy and firm, they won’t get pressed by accident in any case. This key lock function bears the biggest bug of the firmware, as I see it: the screen only turns off when key lock is engaged – it never turns off when the buttons aren’t locked. The life span of an OLED display is very short, and I know this screen will burn out in a short time when it’s constantly active. It’s the same screen model as on Sansa Clip players, and I know how those get burned out simply by letting them charge attached to a computer, since they don’t turn themselves off for over half an hour (which is quite a serious bug with the Clip’s firmware, in my opinion). Not to mention that the screen is much too bright when I use the E7 at night. FiiO definitely needs to implement a screen-timeout feature that works without key lock engaged – disengaging the key lock every time when one wants to do a simple task like changing the volume is a major hassle and hindrance – and, as already said, in most circumstances it’s completely unnecessary to lock the keys to begin with, but there’s no other way to turn the E7’s screen off so far.
The next functions in the firmware are to set the maximum volume the amp will go to, with its rather precise 60-step volume control, and the volume memory function, which will remember the set volume after turning the amp off. Without volume memory, the amp resets itself to volume level 10 at the next start. Be careful when using this function – you don’t want the amp to deliver its maximum volume to your ears when you’ve just switched from full-sized headphones to efficient IEMs.
The last point in the main menu leads to the system sub-menu, which shows the current firmware version (which I hope is user-upgradeable, not factory-hardcoded), the total runtime of the amp (my favorite geeky option of the amp, which can be set to zero again via the reset hole), and a function to reset the amp to its default settings.
This covers all the options found in the menu, but I have still some nitpicks and suggestions for improvements and better usability to make. For one, it would be very welcome if the menu points would loop – so when you reach the bottom of the list, it starts at the top again, and vice versa, without getting stuck. The scroll speed through lists and for volume control could be a bit faster as well; it’s a bit on the slower side as it is. The menu could use a longer timeout, it automatically jumps back to the main screen after only 5 seconds, which really isn’t much – 10 or 20 seconds would be a better timeout. A bug in the firmware is that the first volume button press doesn’t execute the desired function, only the second consecutive button press does: you press the volume button, it doesn’t change the volume, you press it again, and it changes. This would make sense if the screen would actually be turned off and the first key press activates the screen – but since the screen is always on, this doesn’t make sense. Weirdly enough, the menu button reacts at the first press. The key lock mechanism is weirdly implemented as well – I often don’t get it to unlock on the first try – but once again, key lock wouldn’t be needed if the screen turned itself off without it.
Last but not least, speaking for all the people with imbalanced or damaged hearing out there: I’d love to see a pan/balance feature in a portable headphone amp. The majority of MP3 players available today doesn’t have this most basic of all functions (after the volume control). I have no idea why only Rockbox, Cowon, and Archos are the last ones left to have pan/balance controls, but it certainly sucks to be me. I have about 4dB lower hearing in my left ear (childhood ear infections, but I still hear 17 kHz treble just fine), and I cannot use any MP3 player that doesn’t have a balance control. With an amp that adjusts the pan/balance, I could use any MP3 player I like, a whole lot more brands would be accessible to my ears. I know from our forums that quite a few people are like me, and this amp seems to have all the hardware and firmware prerequisites to help this niche market of ‘lopsided ear invalids’. FiiO, can you hear my pleas? The E7 would become a seriously invaluable tool for me and a lot of other people that way – and you would gain my eternal gratitude.
In the end, the E7’s firmware delivers very nice and useful features, but it could do with a little more polish, some bug- and usability fixes. Don’t
get me wrong, there really aren’t any showstoppers or overly severe bugs – but the amp could be made even more awesome with a little more firmware hacking.
First things first: I’m not going to look for differences in sound quality where there aren’t any. I leave the placebo and make-believe to others – there are enough people out there who use lots of flowery words for describing sonic traits that don’t even exist, or sound exactly the same on all other amps available (except the ones that aren’t good… or tube amps, which sound different by design). A good amp is a good amp is a good amp – it sounds neutral, has a linear frequency response, low distortion, low noise floor, good channel separation, and other factual constants. These aspects often change depending on the headphones attached to the amp; they’re dependent on impedance, sensitivity, and other variables. All in all, there is negligible difference between good amps, they do not have a characteristic ‘sound’ – if they would, they’d be no good amp.
This being said, the E7 is a good amp with almost any headphone attached. As most portable amps do, it hisses a bit with overly low impedance and highly sensitive phones, but less than many other amps do. FiiO’s own E5 hisses about as much as the E7, the E3 hisses a lot more – but it can be forgiven, considering its $8 price tag. Either way, as soon as you get a bit above approximately 32 Ohm impedance and/or below 115dB/mW sensitivity, the E7 becomes dead silent and ‘black’.
I’ve mostly compared the E7’s USB performance to the headphone output of my Echo AudioFire 4 sound adapter, and its analog performance to the Sansa Clip’s headphone output in listening tests. Both can be seen as very solid real-world benchmarks in their particular field of application.
The only real, noticeable issue with the sonic performance of the E7 to my ears is that it could have a bit better stereo channel separation, also known as crosstalk. While in portable use it’s about the same as most MP3 players (except some Sony models, the iPhone 3G, and maybe a few others which have above average crosstalk behavior), when compared to my AudioFire’s headphone-out, the E7 is somewhat narrower, more congested in its stereo imaging. But that’s pretty much the only thing that’s not so high quality as far as audio reproduction goes. It’s only really apparent in a direct comparison; it’s certainly not a huge flaw in my opinion. Other than that, the E7 performs very well. My RMAA results pictured above show some irregularities with distortion and noise when the E7 is used in USB mode with low impedance phones, but I couldn’t really hear anything detrimental concerning that matter with my own ears, compared to when the E7 is used via the analog input.
Another praiseworthy matter is that the E7 drives my 300 Ohm Sennheiser HD 650 phones just fine. A lot of misinformation and legends have been spread by ‘audiophiles’ about these phones. While they’re certainly not the most suitable to be used directly on most MP3 players, they are not that overly hard to drive and they don’t need a super-powerful amp, as is often claimed. The HD 650 sound pretty much the same driven by the FiiO E7, the AudioFire 4, as well as my overly beefy tube amp, the Woo Audio 6 (which adds nice harmonic distortions, but doesn’t drive the HD650 any ‘better’ than the other ones, in the grand scheme of things).
All in all, the FiiO E7 performs well with about any phone you throw at it. Personally, I’m really picky about even the tiniest bit of background hiss, so I wouldn’t use the E7 with very difficult to drive high-efficiency IEMs like the Ultimate Ears UE11, Shure SE530, Sennheiser IE8, and similar ones – but I really like how the E7 performs with my Phonak PFE, Hifiman RE0, Ultrasone HFI-780, and, as already said, even the Sennheiser HD 650.
I must say I’m quite surprised how nice the E7 turned out to be. It’s a solid performer with almost all kinds of headphones, both as a portable amp and as an USB sound adapter. FiiO’s developers sure made a laudable effort coming up with all the nifty features found in the amp’s firmware – it could still use a bit of polish, but the E7 is a truly unique hybrid product already. Physically, the amp might be a bit big for on the go, but compared to many other so-called ‘portable’ amps the E7 is still a lightweight. It needs to be seen if the novel idea of using a screen in an amp is the best in the long run, but it sure opens up a whole new world of possibilities and features. I’m sure FiiO could implement the firmware fixes and usability improvements I suggested above easily into a software upgrade for the amp, making it even more rockin’.
The E7’s price/value ratio is excellent; one really gets some bang for the buck – sound, build, battery, and functionality are all great considering the quite fair asking price. If someone’s got a portable player that does lack some quality headphone output, or is in need for a computer sound card that can properly drive one’s headphones, I would certainly recommend the E7 to any audio aficionado – not only the budget-conscious one.
- Good sound quality
- Useful firmware functions
- Excellent battery life
- Good build quality
- Digital volume control
- Plug’n’play – no drivers needed on modern operating systems
- Great price/value ratio
- Firmware could do with several usability improvements
- Channel separation/crosstalk could be a bit better
- A bit big and heavy (only relevant for portable use, of course)
- OLED might not be the best display technology for this application
At the time of writing the E7 isn’t available for purchase. It should be coming to stores, real and/or virtual, soon.