Fiio E02i Rocky

Average User Rating:
  1. bowei006
    "Small cost, small device, "
    Pros - Cost, function, amplifier, micrphone
    Cons - Finicky to use, size is still a bit big.
    FiiO has just unveiled a new headphone amplifier codenamed Rocky. It is a update to the aging E1 and E3 designs. It features a small size but packed with features. It has a built in headphone amplifier, "High SNR" Microphone, bass boost, bypass option, 10 hour battery, inline control compatible with iPhone, metal shielding to better "shield the disturbance"(EMI presumably), and "excellent circuit design".

    Build Quality:
    As expected of FiiO's new builds, it is very well made. IT is more or less aluminum on the outside bar the cable, and the top and bottom hard plastic black pieces. There is little play on any of the metal sub units and everything is very nice. The cable itself and the 3.5mm jack is no exception. The metal and plastic used on the jack is also of high quality. No wiggle and feels excellent. Talking about the build itself, I would have preferred FiiOs new black styles used in the E10 and E17. 

    For photo's on the build, go to the picture section above.

    The cable itself is nice. No problems really. The base connector to the E02i does not feel like it can easily pull out or move. Although sadly the cable itself is prone to twisting into weird loop positions and also when using with PMP, after turning the PMP a few times, the cable will get weird turn rolls. I fear this in the long run will put turning pressure on the base. Only time will tell. Lastly, I wish FiiO put their logo on the metal part of the jack connector. I am talking about like the RC UE1. Be it horizontally or vertically across. That would have looked very nice.

    Well so how does it feel on a day to day basis. I used the E02i pretty exclusively these past few days putting it through conditions of using it with headphones while doing chores, watching kids(how easy it is to pause and do other sutff), and also when running and various other activities. The E02i itself has a nice body but there are some issues. First of all, like I said earlier, cable twisting and looping that puts and turns the E02i into weird positions as the cable is putting a clockwise is counterclockwise "spin" on the device or if the cable rolls up. The rolling up is probably due to it being rolled up for the package and may go away but the twisting doesn't. This makes it quite annoying and bothersome sometimes as you have to go and fix the whole device setup. Which brings me to my next point. There are too many wires. The E02i comes with two clips but that doesn't help much and is actually a nuisance. The clips were weirdly chosen in my opinion. They are dual side open or whatever they are officially called. There is one that has both sides open Think of the Channel brand logo. Why is this not good? Because then when you pull your headphones off, the clips that are meant to be with the E02i will sometimes stay with the headphone wire and not the E02is. What FiiO should have used is both clips that is closed at one end and open on the other. So think of the Channel logo again and make one side fully closed. The closed side will of course be the E02i wire side. This guarantees that it can slide but will also stay on the E02i without falling off or having the user to worry about it. Currently only the top one(nearest to E02i unit) has a single closed while the bottom isn't. Continuing about the wires. There will be a mess of wires with the E02i. From your headphone wire, comming back up and into the E02i which is probably clipped to your shirt, with the E02i wire running back into your pants. 

    And keep in mind that I am already using a portable headset with one of the cleanest and just right length of cables I have. It doesn't look good to have it clipped and not having it clipped defeats most of its purpose being a microphone, and controller. So businessmen using this. Clip it, inside your suit. Next would be the plug in and out pops. There is a warning about not having headphones plugged in while the E02i is on or something like that but sadly it is something that isn't always possible. With the E02i on and headphones plugged in, plugging the E02i into a device will sometimes if not generate a pop, plugging it out will get you crackles. Circuit design I am guessing. Not very favorable but I can live with it. The E02i itself as it matches with devices volume controls is not recommended for sensitive IEM's so it isn't too big a problem, although those with more sensitive devices beware.

    I would also recommend that FiiO make the clip stronger. It is decently strong but when clipping to a polo shirt or other areas, it does feel very slippy with the metal not even clipping so maybe a slightly stronger spring next time. 

    Lastly would be the volume control. IT is a bit unfavorable but also understood. Generally when you press and hold the down or up button on your iPhone or iPod, the volume will go up 1 step, pause for a fraction of a second and if it detects that you are still holding it, raise or lower the volume in quick steps. The E02i does not do this. Each press equals one raise. This is quite annoying but also understood why which I will get to later. Most will be used to the regular phenomenom I mentioned above so it will be quite weird.  I don't know if this would even fit but the cable itself is also a thing to think about. Frankly it is hard to even argue for a shorter or longer cable as each person and clip location is different. This isn't a critique as much as a product specific inconvenience that is already standard. 

    Update: The clip is a real problem for cloth fabrics that I use. It more or less is only held there from the top part of the clip and has been falling very easy with vigorous running or at the slightest touch that pulls outwards. This is not very good for running on most materials.


    The controls of the E02i work very well and as stated. I am using this on my iPhone 4S. The volume control like I mentioned above was my only chagrin but that is also justifiable in that this is an amp. I found that when using the E02i, as it is an amp, it raises my portable headphones to dangerous volumes, which is one reason why I think FiiO may have not used the system Apple and many other companies use but it could be something else. I personally do not know to support asking for the hold and quick volume raise or not as some with easy drive headphones may get damage to their hearing if they hit it by accident too much.

    The center button controls are quite simple and easy to use and remember. Here they are:

    "③Music control /answer call
    - Press one time: play or pause
    - *Slightly press it twice quickly and continuously: next song
    - *Slightly press it three times quickly and continuously: previous song
    - *Slightly and continuously press it twice, press longer time for the second time: Music forward
    - *Slightly and continuously press it three times , press longer time for the third time: Music backward
    **It would be valid when the interval of continuously and lightly pressing time is within 1S.
    - Long press it until hearing notification tone : voice control function
    - Under voice memos, slightly press one time : start recording, press one time again : stop recording
    - Phone call: press one time is answering /hanging up the call
    - Incoming call, slightly and continuously press it for 2 seconds means refusing to answer the call." -FiiO

    They work well and are very responsive. Only slowdown in controls would be due to the phone itself generally if it is doing too many operations at once. The controls do not require power to be used in the sense that if the amp runs out of power, you can simply switch to OFF/Bypass position and controls and microphone will still work.

    Voice control:
    Voice controls are good. It is impossible to do testing of iPhone mic with Siri and then EO2i as the results differ in such a real world environment of changing voices and pitches and what not. But in a quiet environment or even one with more noise, the E02i performs admirably. As seen in the microphone test video later on you will note some noise in the background but that does not interfer with day to day operations. However I am worried for real world loud environments. iPhone 4S and 4 uses dual microphones and a built in Audience chip with "state of the art" technology (that is more advanced in 4S than 4) to hear and decipher what it is you are saying. I believe the Audience chip used to decipher and quiet down environments and isolate words will be in use with a microphone as it is built into phone audio chips itself but I can not guarantee that. I remember that the chip uses data from the iPhones top microphone to isolate what is the voice and what not so it may not be using the iPhones technology. I have not used in loud environments and won't have a chance to so results may not be as good.

    Otherwise everything is fine. Queueing up Siri takes a long hold until the Siri notification noise pops up but as the E02i is using the iPhone's already built in software, it works seemlesly. While listening to music. The long press will phase the song out quieter and quiter until it stops(a fast process of 1 second) and Siri pops up. You then say your instructions and it goes away. Some people may be annoyed that every subsequent queueing up of Siri no matter what even if it is open takes a long press but for drivers in a car, this little thing is not bad and also doesn't mess up controls for playing the music or closing Siri. With Siri gone by pressing the center button once, your song restarts seemlessly again. Audiophile devices can now be nearly as convenient as consumer ones! Listen to music with your favorite headphones and enjoying it while still be able to queue up Siri and other controls!

    It boasts a high SNR but I still find more noise in it then with the iPhone's own two mics but that is too be expected as the iPhone uses dual microphone noise isolation technology with a "state of the art" Audience chip. But none the less, it works well. Calling other people have no problems. I and they sounded clear. They sounded even better as I could now use my headphones to hear them and just speak and have my favorite song come up after I am done! Of course I realize that voice over cellphone is very low quality but hearing it is just better I guess. More personal and using my audiophile portable headphones to boot! I was quite suprised and happy to be picking up calls, using Siri and then listening to my song. It is truly a new experience. I would want a more powerful amp and better one but that may just be stupid. I won't be using Q701's in the car or walking around the city and most portable headphones will get more than enough from the E02i.

    Also, note that plugging the E02i into most computers and into your iPhone will usually by default allow you to use the E02i's mic to record. The Microphone does not require power to be used in the sense that if the amp runs out of power, you can simply switch to OFF/Bypass position and controls and microphone will still work.

    Sound Quality:
    My reference setup will be:
    ComputeràS/PDIFàAudio-gd NFB 12.1 Dual Wolfson WM8741 Fixed DAC outàCustom O2 with Burr Brown OPA2228.

    So how does it sound. Well the E02i is warm. Very warm. It is not as universal as many of FiiO’s other amps due to this but at a price point of $29 USD, most headphones used with it won’t really be picky in any case. The E02i is a warm and slightly muddy amp. IT does improve (more on what I mean by improve later)  on some things such as bass and has artificially sweeter sound but in the end still has trouble keeping up with other dedicated portable amps in the price bracket.  It’s soundstage is quite small even for a $30 amp when compared to others of the same bracket. Everything is very tight packed together with also less separation that you would expect. The saturation and bass impact of the E02i however sets it apart. For true audiophile’s.  This is a no no and is not generally wanted. But at the price bracket that the E02i targets, the E02i may be very much wanted for the effects it brings of warmness and bass impact.

    I didn’t really go into depth there as well in my opinion, unlike headphones, the regular sound quality section is just short and sweet, the comparison section however is where things really matter as come on. I can say warm and muddy for any amp up to $300 but compared to what is the main question.


    The amp does not work like a traditional one where you first set your pmp's volume and use the E02i's volume controls to control the E02i's amp. The E02i piggybacks on the PMP or iPhone/iPod's own and when you press + on the E02i, the iPhone will raise by one step which is a nice innovative dual amping way to do such a thing. It is still dual amping as it is using a 3.5mm jack but the way it piggy backs onto the iPhones interface already is a nice new thing.

    E5 and E02i:

    The E5 wins and undeniably beats the E02i in sound. The E02i suffers from lack of separation and or soundstage when compared against it’s many previous gen ago brother the E5. The E02i is just a very warm solid state amp in the sense that it just makes everything more saturated and vibrant but overly vibrant.  This does make it sound sweeter and more different to others but in terms of sound. The E02i however does have some of FiiO’s improvements, noticeably in the bass section. With both devices with bass boost OFF, the E02i delivers more punch and impact. However it does this with some not really punchy effects. Still better than the E5’s punch though. I won’t say which is better as some enjoy more punch at this price bracket even if it is muddy while others would rather not. The bass boost on with the E02i also delivers and amplifies the effects of the E02i even more. This means even more warm vibrancy and muddy bass punch compared to the E5 which handles it more sparingly. The bass boost on the E5 however in terms of technologically speaking isn’t as good as the E02i’s in my opinion. The E02i’s of course is more muddy in that it has car sub effects but at the price bracket, it significantly has more punch and just bass than the E5 could ever deliver.

    iPhone 4S headphone out and E02i:

    The E02i wins here. But not in an overall kind of sense. Some audiophiles would rather use iPhone or their headphones out instead of using with E02i’s amp as it doesn’t over saturate the sonic objects of the range and is more “neutral”  in some senses. But even with that said, the highs, vocals, mids and lows just sonically in a step by step comparison generally have the E02i winning with more enjoyability and some improvements. Such as steadier high frequencies and a punchier low and more “lusciously” warm vocal. The soundstage on 4S direct out is larger by a tad bit. Initially it may seem like the E02i may have an advantage over soundstage but it only feels that way initially. The direct out on the 4S has more wiggle room and spreads. I will say that the warm added bass on the E02i lessens the appearance of soundstage. With all said, I personally prefer the warmer sound as opposed to the direct out’s and the added punch, although on the muddy side is welcome. The added sonic improvements in softening out some highs and warmer vocals are also a nice side to see.

    Sonic Conclusion:
    The E02i is a good “unit” for $29 USD approx. It is not sonically as clear as the popular E5 of the same price bracket , nor is it superior in an audiophile sense. However it is superior in the things it does for the users. It adds more warmth to the music and more bass impact and overall. The added warmth for users at this price let it sound different than you would from iPhone or iPod direct out and the added bass impact and bass in itself is also welcome. I am making very generic statements on what I believe users at the price range of $29 USD find or will notice but my observations have generally shown me that they like added warmth as it shows difference and also the bass is what they also look for.

    Overal Conclusion:

    While the E02i does suffer sonically when compared to it's cousin the E5, for the features it packs, it is a nice update to the FiiO line. It will dual amp and has a few nit picks here in there whilst using it but overal, it is a nice portable device to have with your smartphone. I do not know if it will work with other devices yet. Tell me in the comments on what ones you tried it with. But the controls work very well, it is a very intergrated product for use with a Smartphone and mainly an iPhone 4/4S to be exact doing operations smoothly and nicely. It has some nice bass boosting properties but the biggest point is just how it has a microphone for use in the car while using your favorite headphones as well. There are other things and annoyances and compatibility issues on using sensitive headphones, plugging in the E02i creating a pop(manual says to not have headphones plugged in, but hey, hard to follow) and also the tangly wires. This is not realy just even an amp anymore so I can't say to recommend it to an amp wanter. This is mainly a device for users that wants to be able to use their smartphones(or iPhones at the moment) for many of it's features and should be bought depending on if you want to use it for the voice control, amplification and all the other nice features that I have went through above.

    If you are looking for this as just an amp than look elsewhere. For the price, it's amp is a 7/10. Very average, sonically disapointing at times but with a nice bass that can sometimes make up for it. However for it's combined function, it is a 9.5 if not a very good device. It is solidly built and it's functions work seemlessly with the iPhone and Siri. The in line controls, and Mic are done very nicely and the bypass switch that I initially thought was redundant makes a world of difference.

    Critiques: The first critique would be the clips clamp force and design, the clip could only be more "elongated" and not like the E5's square shape. This leads to weird clipping strength and ability to stay on the person. This changes depending on where you clip the device. The second would be why the second cable clip and slider didn't use the closed and open loop design as the first cable clip on the E02i, there is no point in my opinion. I don't know why but flipping the switch for on and off and bass boost, is a bit awkward sometimes, it isn't as quick as the E5's switch and depending on the angle you push it at, it may not move as you are pushing at it in the wrong angle and thus applying pressure to the wrong place. The Microphone is decent and good for close up vocals but it is not exactly high SNR as one would expect to use from a real microphone, it is quite good for personal talking but the dual way cancelling mic of your iPhone is better, but of course, you bought the E02i so you can have your phone in your pocket. Lastly would be the pops. It boasts excellent circuit design but yet it is still clouded over by the pops you get when unplugging or plugging in your headphones while the device is on. The volume of the pops vary from device but I have had some VERY loud and unpleasant pops from it. Putting a sticker warning of it is nice, but not productive. It means that the problem is known, but the problem is still there. I would hope an update comes out to fix this pop. Everything else are small issues but the pop needs to be fixed.

    Audio/sonic quality: 7/10
    These scores are based on price. I do not recommend the E02i as a standalone amp, or as a standalone Mic or as a standalone song control unit as there are others. But together, they make a combo that someone that wants a unified device with their iPhone can't resist!

    Output Power: >70mW @ 32 ohms;   18m@ 300 ohms
    Headphone impendence Range: 16 ohm~300 ohm
    Freq Responce:20 hz~20KHz
    Power supply: Li- ion rechargable
    Size: 23.33mm x 57.3mm x 15.3mm (including the clip)
    Length of the wire: 800mm (80cm)
    Weight: 27 g
  2. pmwoodward
    "Fiio E02i Rocky impressions"
    Pros - SQ, size, interfaces very with well with Apple sources
    Cons - not very durable. the right channel stopped working after a year of light, careful use. Defective connection at the 3.5 mm jack.
    I would like to point out from the beginning that I have not every tried any other portable amp. Also, I am using them with a very entry level pair of the headphones (monoprice over the ears DJ). A coworker bought the Fiio E02i, so I naturally was curious as to what it would do. While I was expecting more volume perhaps at the SQ, what I found was a substantial improvement overall. It makes my headphones sound twice as good. I naturally purchased my own. I have no doubt that the limitations of this amp would likely be obvious with quality source/cans. But, for very small $$, I am thrilled with the results. I realize that giving a rating is rather useless as I have compared it to nothing else.

    ***4/25/2014 Update***

    I will now follow up after a bit over a year of use. I have upgraded to the Digitech Pro Monitor Headphones which are an enormous upgrade in SQ and especially comfort over the Monoprice DJ cans. The Fiio Rocky was easily up to the task better quality Digitech Pro Monitor Headphones. Just recently, the right channel stopped working on the Fiio Rocky. If I twist the cable near the 3.5 mm jack just right, the channel comes on. I have not abused the cable/connector at all. At $18, I guess I cannot complain too much. I am guessing that the very small gauge cable added to the eventual failure. Looking back, I am glad I bought it, although it really should have lasted much longer. I have adjusted my ratings a bit. I I do not think I will buy another Rocky. I am looking seriously at the E17 Aspen now.