Author: Brooko

Review from: Head-Fi

→→ Read the original article on Head-Fi: >> Click here

INTRODUCTION

When I first came to Head-Fi I was naturally curious about portable amps. When I got my first one (the old E7) I was blown away – the increase in clarity, details, soundstage! Then over time, as I read more, experimented more, and (more importantly) tested more, I can to realise that those benefits I was sure I heard, had mostly come about by simply turning the volume up.  And with the portable amps I was using, I wasn’t volume matching when comparing.  Once I actually started comparing objectively, most of the time those differences disappeared. Sure – there are times when you absolutely need an amp – like with the 320 ohm VE Zens, or if I want to drive my HD600s portable, and there isn’t enough volume. But for a long time with my portable listening, I stopped carrying a portable amp.
 
Then around Sept/Oct 2014, I worked with Fiio to set up a “Down Under tour” for their new X1 DAP, and as a bonus they also threw in their E11K amp. At the completion of the tour, I offered to buy both units from Fiio (and yes – I paid real money for them), and the last 12 months has given me a whole new perspective on portable amping, why you might want to use one, and why the budget prices E11K (A3) portable amp from Fiio should be considered.
 
ABOUT FIIO
 
By now, most Head-Fi members should know about the Fiio Electronics Company.  If you don’t, here’s a very short summary.
 
Fiio was first founded in 2007.  Their first offerings were some extremely low cost portable amplifiers – which were sometimes critiqued by some seasoned Head-Fiers as being low budget “toys”.  But Fiio has spent a lot of time with the community here, and continued to listen to their potential buyers, adopt our ideas, and grow their product range.  Today, their range includes DAPs, portable amps, portable dac/amps, desktop dac/amps, earphones, cables and other accessories.
 
Fiio’s products have followed a very simple formula since 2007 – affordable, stylish, well built, functional, measuring well, and most importantly sounding good.
 
DISCLAIMER
 
The E11K (A3) portable amplifier that I’m reviewing today was purchased by me (direct from Fiio) at the end of the Australasian tour I organised.  I have no obligation to write this review, I am not affiliated to Fiio in any way, and this is my honest opinion of the E11K (A3).
 
PREAMBLE - 'ABOUT ME'.
(This is to give any readers a baseline for interpreting the review).
 
I'm a 48 year old music lover.  I don't say audiophile – I just love my music.  Over the last couple of years, I have slowly changed from cheaper listening set-ups to my current set-up.  I vary my listening from portables (Fiio X5ii, X3ii, LP5 and iPhone 5S) to my desk-top's set-up (PC > USB > iFi iDSD).  I also use a portable set-up at work – either X5ii/X3ii > HP, or PC > E17K > HP.  My main full sized headphones at the time of writing are the Beyer T1, Sennheiser HD600, and AKG K553.  Most of my portable listening is done with IEMs, and lately it has mainly been with the Dunu DN-2000J, Jays q-Jays and Alclair Curve2. A full list of the gear I have owned (past and present is listed in my Head-Fi profile).
 
I have very eclectic music tastes listening to a variety from classical/opera and jazz, to grunge and general rock.   I listen to a lot of blues, jazz, folk music, classic rock, indie and alternative rock.  I am particularly fond of female vocals.  I generally tend toward cans that are relatively neutral/balanced, but I do have a fondness for clarity, and suspect I might have slight ‘treble-head’ preferences.  I am not treble sensitive (at all), and in the past have really enjoyed headphones like the K701, SR325i, and of course the T1 and DT880.
 
I have extensively tested myself (abx) and I find aac256 or higher to be completely transparent.  I do use exclusively redbook 16/44.1 if space is not an issue.  All of my music is legally purchased (mostly CD – the rest FLAC purchased on-line).
 
I tend to be sceptical about audiophile ‘claims’, don’t generally believe in burn-in, have never heard a difference with different cables, and would rather test myself blind on perceived differences.  I am not a ‘golden eared listener’.  I suffer from mild tinnitus, and at 48, my hearing is less than perfect.
 
For the actual listening part of this review I used the E11K (A3) mainly with my X3ii or X1 DAP, and a little bit with the iPhone 5S. Observations about the E11k (A3) are taken from the past year I’ve owned it. This is a purely subjective review - my gear, my ears, and my experience.  Please take it all with a grain of salt - especially if it does not match your own experience.
 
FURTHER NOTES
 

1. Although Fiio are in the process of rebranding/renaming their portable amp line from E series to A series, from this point I’m going it simply call it the E11K.  It’s just easier.

2. Volume matching was done with a calibrated SPL meter and test tones (1 kHz) when required for comparison.

3. Frequency response and distortion measurements were taken using a relatively cheap Startech USB soundcard (which measures pretty well – 0.012% THD and 0.024% THD+N – which was consistent at 300 Hz, 1 kHz and 6 kHz @ -3 dB volume as suggested by ARTA using loopback). I combined this with a licensed copy of the ARTA measuring suite. The soundcard has a calibration adjustment applied – so that it measures dead flat from 20 Hz to 20 kHz.

 
WHAT I LOOK FOR (NOW) IN A PORTABLE AMP
 
I thought I’d list (before I start with the review) what I would now look for in a portable amp. This is useful to remember when looking at my reasoning for scoring later in the review.

1. Genuine portability

2. Good battery life

3. Clean, neutral signature

4. Easy to use

5. Low output impedance

6. Reasonable output power – should be able to drive IEMs and earphones up to 300 ohms

7. Good gain control

8. Value for money

 
PORTABLE AMPS I’VE OWNED IN THE PAST
 

1. Fiio E7, E11, GoVibe Porta Tube, Headstage Arrow 12HE 4G, Beyerdynamic A200p

2. Current portable amps E11K, E17K, VE Runabout

THE REVIEW

PACKAGING AND ACCESSORIES
 
The E11K arrived in Fiio’s retail packaging – a white, red and black box measuring 130 x 130 x 25mm. The front had a picture of the E11K, and the rear has some specs and other information in English and Chinese.
 

Retail box - front	Retail box - rear	Retail box - profile

 
Opening the outer retail box reveals an inner box with a foam cut-out (securely holding the E11K), and a secondary box for the accessories.  The accessories include:
 

1. 6 stick-on feet

2. 1 x 3.5-3.5 mm cable (Fiio’s L8 mini to mini)

3. 2 rubber stacking bands

4. A USB to mini-USB recharging cable

5. Warranty and instructions

Inside the box E11K + accessory box	Accessories	Cables - interconnect and USB charging

 
The entire package is practical, covering everything you initially need for the E11K.  Materials are all good quality. If there was one thing I’d change it would be ditching the silicone feet (they slide around on the body) and instead including one of their silicone stacking pads.
 

Manual and warranty envelope	Stacking bands	The Fiio E11K

 
TECHNICAL SPECIFICATIONS
 
The table below lists most of the relevant specifications for the E11K.

 
BUILD / DESIGN
 
The E11K is rectangular shaped with slightly bevelled edges, and a slightly curved top side and under side. The main body is a solid machined block of aluminium. At one end is the Alps potentiometer – nicely nestled between two raised protective arms (so it’s more difficult to accidentally bump the pot), the high/low gain switch, and the on/off bass boost.
 

Front/top panel	Gain switch and better view of edge bevelling	Rear/bottom panel - ports

 

At the other end is the 3.5mm headphone out jack – still nice and firm after a year’s use, a blue LED (solid blue when on, flashing blue when charging), a micro USB charging port, and the line-in 3.5mm port. Overall the external build is really solid, and even after a year my unit has very few scratches or bumps. The curved surface feels good in the hand, but it is the one design error I think Fiio made with this amp. It’s simply not that well suited for stacking (and that is what a portable amp will be mainly used for after all). If you’re using otherFiio gear with it, then their stacking kits and silicone pads really help – but the curved surface wasn’t one of Fiio’s smartest choices in this case.
 

Underside	In use LED light	E11K charging - LED slowly pulses

 
Opening the unit up, it’s easy to see the curved one piece body, and also how compact and tidy the layout is. One thing I also noticed was that the underside is fitted with a shroud.  I guess this has two possible uses – as a guard against accidental static flashes from the board – but maybe also as an EMI shield.  Compared with the older E11 (which I used to own), I have had no problems with EMI (and with the old E11 this could be an issue).
Some may find it a bit strange that the ports are at the opposite end to the volume pot – but I actually (over time) have found it quite natural. The good thing about this configuration is that the volume pot, bass boost and gain switches are very easy to get at (no cables getting in the way).
 

Opening the E11K	Note the curved aluminium body	Battery and caps

Ports exposed	Underside has antistatic pad/shielding	Close up of the caps

 

HEAT AND POWER
 
So far I’ve noticed no heat build-up at all with the E11K.  Even after a couple of hours (driving my HD600s), it’s still cool to touch.
 
For output power the E11K uses the OPA1642 for preamp and the AD8397 as its power amplifier. Fiio rates the target headphone impedance as 16-150 ohm, and I think that maybe a lot of people see this and automatically assume this little unit can’t drive a headphonelike the HD600 (300 ohm properly).
 
But as I do the final edit of this review, I’m sitting with the X3ii feeding the E11K, then into my HD600’s.  Volume on the pot is around 3/9 (low gain), and I’m getting a very comfortable 65-75 dB with minimal effort.  This is my usual listening level so I’m pretty content. Taking the HD600 off my head, and cranking to maximum volume gives me 90 dB peaks.  High gain would add another 15 dB to take that to 105 dB – more than you’d ever need.  And at no stage do the HD600 feel under driven.
 

E11K with HD600, VE Zen and DN-2000J	E11K with DN2000J	E11K and X1 (with stacking kit)

Note that although this series of photos shows E11K with Fiio X1, the X3iiw as actually used in testing

 

With a variety of headphones / earphones at my disposal, the test track “Sultans of Swing” by Dire Straits, and X3ii feeding E11K via line-out at low gain – these are the approx. volume settings to get to a comfortable listening level (for me) at around 70-75 dB on low gain:
 

1. HD600 (300 ohm, 97 dB SPL) = ~ 3-3.5/9

2. VE Zen earbuds (320 ohm, 106 dB SPL) = ~ 2.5-3/9

3. Trinity Delta IEMs (16 ohm, 110 dB SPL) = ~ 2/9

4. Dunu Titan1 IEMs (16 ohm, 90 dB SPL) = 2-2.5/9

5. AKG K553 Pro (32 ohm, 114 dB SPL) = 2.5-3/9

6. Dunu DN-2000J (8 ohm, 102 dB SPL) = 2/9

 
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