Thought I'd post a first impression of the E17. By way of introduction (first post here lol) I'm a member of Team XBMC who contributed to the new audio engine in place for v12 "Frodo" and an ardent audio junkie.
A couple of test scenarios:
1) as a portable amplifier essentially double-amping my faithful iRiver H10 (RockBox'd ofc), and
2) as a USB DAC/amp connected to a PC
Test gear can-wise was the ol' Koss Porta-Pro's, some middling Pioneer closed over-ears, and the Sennheiser HD558's. First off, I'll rule out any serious review of the first two cans. The Porta-Pro's are so easy to drive they benefited little over the stock 18mW output of the iRiver, let alone when powered by PC soundcard. And the Pioneer's are just to tainted to my ears to really convey much improvement, so I'll focus only on the Sennheiser HD558's, partly because they seemed lacking with the iRiver DAP and partly because they are such a hot seller of late. Lesson here is: if you have very easy-to-drive cans like the PP's or just lacklustre gear like the Pioneers, this unit won't help you much.
Okay, onwards with the HD558's.......
1) As much as I was thrilled with my initial audition of the 558's, their performance when driven by the iRiver was underwhelming. The DAP just couldn't drive them to their full potential. Soundstage was somewhat lacking (despite it being a forte of these open-ear cans) and bass was muddled. The only thing that shone when driven by the iRiver was the stellar mid-highs of female vocals and brass instruments. Enter the E17. Even though we're just utilizing the iRiver's dated DAC, the amplifier power of the E17 was just enough to really make the 558's shine. Bass was tighter and punchier (and the 558's lack bass), the air or seperation improved, soundstage widened to the full potential and the mids and highs kept faithful to the Sennheiser signature, albeit brighter with the 558's than some of the darker Senn's. Outside of the more pronounced and improved bass, the overall effect was very lively and bright. Accoustic guitar is always a great test of fidelity and timbe, and the E17 brought it out wonderfully. Electronica was clear to a fault, often revealing recording and intrument-quality issues not heard without the amp. Top marks here. The E17 made this combination sparkle, and made the pairing (tripling?) a portable powerhouse to be reckoned with. FLAC's at 24/96 were pristine, punchy and powerful indeed. No audible hiss until far over-driven and distortion point passed. Highly recommended for a portable kit.
2) Powered from a PC with a bog-standard RealTek audio chipset, the Senn's sounded great, much better than with the iRiver DAP above. The E17 took it another step, although the improvement was less than with the underpowered iRiver above. Using the digital USB DAC things obviously are much different. Now the E17 is judge, jury and executioner, and it performed admirably for such an economically priced and versatile unit. Tempering my expectations to keep in line with pricing, I found the E17 to be a robust performer, and a stauch improvement over the obvious issues with motherboard audio. Combined with the 558's expect to hear every flaw of poor recordings and poor lossy rips. With quality sources expect fantastic sound, with every nuance clearly presented and minimal noise or other distortions. The unit is more than capable of powering the 558's (a forgiving 50ohms impedence) to unhealthy levels before significant distortion, to the point were it is as likely the distortion is more pronounced from the Senn's drivers than the amp. High-quality 24/96 material soars with this combo. Via the E17's DAC I found some of the brightness noted above smoothed out, and the presentation was quite neutral, and an excellent pairing with the 558's. The tightening of the bass is also a boon to these cans. Highly recommended when you consider the price.
Overall:
Pros: versitility, price, build-quality, packaging (nice felt bag, digital adaptors, rubber feet), compliments 558's well
Cons: no support for 88.2khz - a major issue for those with SACD material, can't easily update firmware
With the caveat of no 88.2khz sample rates, this is a real sweet-spot unit for price/performance ratio, and an extremely versatile unit. Highly recommended for those who are looking for a great all-rounder for both desktop and portable use. Makes me wish for more DAPs with digital outputs (USB/optical/coaxial). A hit out of the park for FIIO in brnging together so much for such a pleasing price.
Recommend.
