Not content with just providing monster-level amping, Fiio added a crossfeed feature as well as the usual Bass Boost knob. Being used to the multi-step Bass control of the Fiio E17/07K, the one level bass boost on the E12 seems a bit primitive. However, the result you get out of that Bass Boost is great and may be the best Bass Boost so far. The strongest boost happens on the low bass section which you don’t see very often with Bass Boost, while the mid bass boost is more mild. And while BB usually adds some degree of boominess, on the E12 it remains tight and controlled.
The crossfeed provides a good job in filling up the center image while not muddying the sound. This is definitely a better crossfeed circuit than what we see on portable amps 4-5 years ago.
Having proven itself with the Hifiman HE-6, I felt that the E12 should be able to tackle everything else in the market with ease, and indeed it does. One of the best E12 pairing is with the Hifiman HE-400 which I really felt the E12 injects enough low treble energy and overall PRaT to make for an enjoyable toe-tapping experience. Strangely though it powers the Audez’e LCD-2 and Fostex T50RP (and its derivatives like the Mad Dog headphone) just fine, I didn’t feel the synergy to be there.
The E12’s fast and energetic sound signature in theory should blend well with headphones that I consider can use some boost in those departments, namely like the AKG K550 and the Sony Z1000, but the result was just okay. The E12 had too strong of a solid state characteristics and personally I’d like a little bit more fluidity in the sound. It does work nicely with UltimateEars’ UE9000 and Philips’ Fidelio L1.
Volume control was good enough to avoid major imbalance with IEMs at moderate listening volumes. There are bound to be some slight imbalance at very low volume levels as in perhaps 99.9% of all analog potentiometers, so if you’re a low volume IEM listener, beware. Also like any other high-powered amps, you’re bound to get a limited range of steps with the volume control.
I used the E12 with a number of different IEMs. A few models from T-Peos (H100, D201, D202), and also FitEar’s 334ToGo (I know). I really didn’t feel IEMs to be the E12s strength. I would rather a lower power level amplifier with better refinement like JDSLabs’s C421 or RSA’s Shadow at the premium range.
This is a real fun and punchy amp for the orthodynamic market. The E12 drives the HE-400 just fine on low gain, but I use the +10 gain setting as it delivers better dynamics for the HE-400. I know that the orthodynamic market is booming, and the E12 is the right headphone for those of you looking for a good amp for your ortho headphone. It’s no Burson Conductor, but the Fiio has enough grunt to make good music with the HE-400.