Saturday, April 18, 2015

FiiO E7 Portable Headphone Amplifier/ DAC Review

FiiO E7 portable headphone amplifier/ DAC
The FiiO E7 is one of the most popular portable headphone amps/ DACs on the market and rightly so.  The unit packs some surprisingly high grade components for such a small, relatively cheap portable device.  The E7 utilizes a Texas Instruments TPA6130A as its preamp and power amp. The relatively high grade amplifier housed within the E7 unit (for its size and price point) is a marked improvement over the much cheaper, poor performing, low powered Cirrus amp chips found in most iDevices as well as other various amp chips found in most portable devices.  The best part about the E7 though has to be it's DAC.  The Wolfson WM8740 DAC chip is a surprisingly high grade DAC chip for the E7's commendably low price.  There are two downfalls to the DAC capability of the E7 however, the first being that the DAC will not work when played from any portable device that uses the auxiliary input on the E7 (AKA iDevices, Sony Walkmans, Zune's or any music player that doesn't have a USB port or that doesn't have the capability to output audio via USB).  Basically the DAC chip is only utilized when using the E7 with a USB cable.  Secondly, the TI PCM 2706 USB receiver in the E7 only supports a maximum of 48kHz, 16-bit sample rate sound even though the Wolfson WM8740 DAC chip supports up to a maximum 192kHz, 24-bit sample rate.  This is simply the limitation of the USB receiver. If FiiO had chosen a higher end USB receiver, the amp could theoretically process a 96kHz, 24-bit sample rate signal via USB.  This is the only true hardware oversight by FiiO, but besides this small downfall the amp sounds great and the DAC greatly improves upon the digital to analog converters in most laptops as well as lower to medium end desktops with onboard or cheaper OEM sound card audio.

Aux line in, dock connector and USB in (left)
Two 3.5mm headphone line out ports (right)
Now for just a quick overview of all the technical specifications for those interested.  The FiiO E7 features a small, dual color OLED (Organic Light Emitting Display) screen that displays volume level, EQ settings as well as battery charge level.  One downfall to the screen is that while the E7 is powered on, the screen cannot be turned off.  The E7 is powered by a 1050mAH Lithium Ion battery that FiiO claims will provide a 80 hours of continuos operation (while I have not actually timed the battery life, I can confirm that it lasts for an extremely long time) Please note that battery life can be effected by the electrical impedance of the headphones used with the amp, headphones that require more power to drive will of course result in a quicker discharge of the battery, but the E7 will be sure to outlast your portable sources battery even when using hard to drive headphones.  The E7 features a three step bass boost EQ function.  This is the only equalization option available on the E7.  Ports on the E7 include a 3.5 auxiliary in port, USB port, proprietary FiiO dock connector for docking the unit with the FiiO E9 desktop amplifier as well as two 3.5mm headphone out ports on the top of the unit (yes the E7 can be used to power two headphones simultaneously allowing you to share your music with your friends). Buttons on the unit include volume up and down buttons, a menu/ enter button and a back/ power on/ off button.  FiiO claims that the amp can power anywhere from 16 to 300Ohm headphones although I would not suggest using this amp with anything over a 150Ohm impedance as the E7 really doesn't perform well with anything higher.  Included in the box is the unit itself, one USB cable (regular USB to mini USB) with two ferrite chokes that reduces signal noise and subsequently increases sound quality. One 3.5mm auxiliary cable (to connect iDevice, smartphone etc. via its 3.5mm jack) is supplied.  A nice soft pouch and a silicon case is supplied as well as a user manual and a rubber band (think smaller, black Livestrong armband) used to conveniently attach your E7 to the back of your portable device.  Some units come with a screen protector, it depends on the date of manufacture.

The FiiO E7 itself is made out of a beautiful black brushed aluminum finish.  While the unit itself is very light weight there is no question in regards to its durability.  I always keep the supplied silicon case on mine to prevent scratching or denting that may occur when I am using the unit out and about.  The buttons are silver and have a slight texture to them and supply satisfying clicks when pushed.  Some people have complained about loose 3.5mm output jacks on their E7's but I have yet to experience this problem.  The FiiO's glossy front glass is a finger print magnet and a possible scratch magnet, but if you used the supplied silicon case and or screen protector you should be fine.

FiiO E7 unit paired with Sennheiser HD 439's
Now for the most important segment of this overview/ review of the FiiO E7: the sound quality.  I will first describe the sound quality of the E7 when paired with my iPhone 5 via the 3.5mm jack (due to Apple switching away from the old 30-pin dock connector to the newer 9-pin lightning connector, there currently is no easy way to connect a FiiO LOD (Line Out Dock) cable to the E7 because it only supports the older 30-pin format) I will then describe the FiiO E7's sound performance when used via USB from my MacBook Pro.  Keep in mind that when using the FiiO E7 via USB with a computer, you are bypassing your computers DAC and amplifier, thus the FiiO E7 will sound exactly the same on ANY computer.  Also keep in mind that when the E7 is paired with an iDevice, the E7 is merely bypassing the iDevices amplifier (if using the line out dock connector) or amplifying the already amped signal coming from the 3.5mm line out on the iDevice.  Using either configuration (a line out dock connector cable, or a 3.5mm line out cable) the E7 will NOT be bypassing the iDevices internal DAC.  When paired with an iDevice or similar portable media player, the E7 will merely act as a headphone amplifier.  The DAC is completely taken out of the equation.  Now that that's out of the way, lets get to it!

First up, the E7 when paired via 3.5mm out with an iPhone 5.  Despite what many audiophiles may tell you about amplifying an already amplified signal, the E7 when paired with an iPhone 5 (in this case) sounds very good even just using the 3.5mm out on the iPhone with the supplied FiiO cable that comes in the box.  A few issues arise when amplifying an already amped signal, one phenomenon is called "amp piggy backing" this issue can be avoided by simply reducing the volume on the iPhone from anywhere to 75 to 50 percent and then increasing the volume via the E7 amp.  The result of this iPhone 5, E7 combo is a much cleaner and tighter signal.  With both of test headphones (Sennheiser HD 280 Pro's, 64Ohms and Sennheiser HD 439's 32Ohms) the bass was much less flabby, much tighter and even more prominent than the standard iPhone line out.  Mid ranges are less recessed on both headphones and much, much clearer and higher ranges sang out just absolutely beautifully. On top of this increase in sound quality, the FiiO E7 is an amp so it allows for louder volumes to be achieved with less distortion in comparison to just using the iPhones 3.5mm line out without an amp.  While both of my test headphones admittedly have pretty narrow sound stages, I did perceive a very slight increase in overall sound stage and instrument separation with this amp, however it was extremely subtle. I like the bass boost function a lot because you can really amp the bass up while avoiding distortion.  Distortion begins to occur in certain bass heavy songs when the E7's bass option is at maximum.  The E7 paired with the iPhone 5 via the standard 3.5mm line out achieves a very warm sound characteristic that I happen to like quite a bit.  Even without the bass boost equalization engaged, its very warm and musical and is definitely lacking from an analytical standpoint if thats what you like.  However, I prefer warmth over analytical any day, but thats just me.

FiiO E7 connected via USB to laptop
The E7 paired with my laptop via USB is a bit less warm and I suppose a tad more analytical.  However, you can achieve absolutely insane bass boost levels even with headphones that distort easily (like the HD 439's that I used) by knocking up the E7's bass boost to max and turning down the preamp level on your laptop to around -3 to -4dB.  I was able to achieve almost Sony MDR-XB700 levels of bass with my rather bass light in comparison Sennheiser HD 439's.  Whats great about the E7 when paired with a laptop is that through using the E7's bass boost options and the equalizations options on your computer you can achieve an analytical or warm forgiving sound signature or anywhere in between.  The E7 is particularly suitable for laptops because sounds several times better than onboard or Intel integrated audio and gets rid of all the signal noise associated with laptops.  If you have ever used a pair of studio monitor headphones on a laptop before, you know what I am talking about.  The E7 tightens the bass and brings out the high ranges more in similar but not as obvious manner as it does with the iPhone 5.

In summary, the FiiO E7 is a great entry level headphone amplifier/ DAC for those who are looking for a little bit better sound quality from their laptop and significantly improved audio quality from a portable device.  The E7 looks great, is built well and sports a nice OLED screen which is a nice feature for an amplifier to have.  It's a wonderful portable solution and a great choice for the entry level audio enthusiast!

Note: The FiiO E7 has been eclipsed by a newer model with a few minor sound and build improvements.  It's called the E07K, check out the Amazon product page HERE.

CLICK HERE for FiiO E7 Amazon Product Page