Pros: Nice detailed, warm and smooth sound, Beautiful vol dial, Powerful
Cons: Power socket on the front, no ability to use as just a DAC, chassis is a little rough
I originally posted this one on my blog here: http://noblehifi.blogspot.co.uk/2012/07/epiphany-acoustics-ehp-02d-review.html . The comparisons will make more sense when read over there.
A big thank you to Oliver at Epiphany Acoustics for giving me the opportunity to test an EHP-O2D from their first batch. This great little chassis is made in the UK and features two devices designed by blogger NwAvGuy (a headphone amplifier and a DAC). Epiphany are not pulling any punches with this model, featuring the ES9023 Sabre DAC and a high quality headphone amplifier for well under £200 is quite a stunning entry to the market. It's the only portable DAC & amp in my group test not to be powered by USB so it's a little less convenient that some, but can it justify that with superior sound quality?
The sound signature is on the warm side, but it's an experience that's clear, airy and beautifully detailed as well as being sublimely smooth. It has a real sense of authority and refinement that I didn't really feel in any of the cheaper rivals so far. The mid-tones feel very alive and surprisingly unaffected by the plumpness of the lower frequencies. Vocals sound wonderfully open and textured as well as benefiting nicely from the warm signature. Treble is amazingly well controlled for something at this level. There is plenty of articulate detail here, whilst retaining a nice sparkle. Sibilance is a surprisingly rare occurrence, even at higher volumes.
The soundstage is very well handled. Headphones that already offer a decent performance in this area get an even greater sense of three-dimensionality while keeping a natural feel. This is the most expensive DAC/amp in the group test, but like many other aspects, the soundstage performs beyond it's price.
I don't feel like any of the warmth on offer here negatively affects the detail. Actually it too feels really rather stunning! Instrument texture and separation is as impressive as the soundstage and will likely have you listening to your music collection over again. I have been really impressed by the balance of sonic strengths on offer from such a small and reasonably priced model, I keep coming back to it after trying many other things and remain impressed.
I am not going to do the usual comparisons here because I can sum it up much more easily, it beats everything else that I have tested here hands down, unless you can't stand the warm signature. Yes, at nearly £200, it's the most expensive of them all but the audio performance does excel it past it's price. The fact that you can just use it's amp and that amp is superb too is the icing on the cake.
OK a little time out for a disclaimer about the sound signature: Even with the Denon AH-D7000, which is renowned for being rather warm on it's own, the addition of the DAC's warmth didn't quite become overpowering for me. On headphones that lack a little warmth (Sennheiser HD800) it could push them just in the right direction for you. Don't expect it to perform miracles and fix something like the AKG K550 if, like me, you are uncomfortable with it's bass presentation, or lack there of. This is a relatively small but noticeable plumpness which, of course, some people will not appreciate, so I just want to iterate this point to avoid possible disappointment. I found the bass more emphasised here than with the Fiio E17, not just bigger, but better textured and more refined. The same was also true compared it to the HRT Headstreamer.
The EHP-02D supports up to 24bit 96khz through it's mini USB connection. Like most DACs with this specification it doesn't need any drivers, or even a restart after it's been recognised, it just works.
Even without power plugging in the USB will recognise the DAC because this section will run from USB power. Be warned: just plugging it in and not turning it on will seem like it's disabled all your computer's audio. The 16v adaptor is purely to power the unit's amplifier. It's great that the EHP-02D can be used as purely a headphone amplifier but unfortunately with no line-out the DAC section can not claim the same flexibility. A line-out through a 3.5mm jack or RCA would have really finished this device off nicely.
The EHP-02D's volume dial is the nicest that I have tried so far. It's metal, has a lovely textured grip and is beautifully smooth in it's operation. Turning the volume up slowly from nothing can present a tiny portion where there is a subtle channel imbalance, but it's at such a low volume that its unlikely to cause any problems. Volume levels were never an issue here, I was able to run the 300ohm Sennheiser HD800 at decent levels without maxing out the dial and that's without even touching the gain button. I can't see anyone having issues of low volume here.
With the gain switch on I did notice some distortion in the higher frequencies at loud volumes a few times, but this never happened with the switch off. Fortunately there is so much power on tap here I doubt that you will need the gain up anyway.
The chassis of the EHP-02D feels strong and well constructed. There was minimal movement to the ports when cables are connected. The only real down side here was trying to keep the surfaces looking clean - the metal felt sticky, greasy fingerprints were difficult to avoid and pretty much impossible to remove. The volume dial seems pretty sturdy, but it's so smooth it could be a vulnerable area if dropped. The addition of a power button is nice, since it's not built into the volume dial like some, it means you don't have to readjust the volume every time you turn it on.
When looking at the front of the device it's clear that the power socket is rather out of place, especially when the white cabled power adaptor is attached. Fortunately there is a black extension lead included which helps it to look a little neater. This issue is a limitation of the amplifier circuit board as it also happens on the EHP-O2 which shares the same chassis. Perhaps Epiphany's next unit, especially if they make a larger desktop model can avoid this but at this price and size it feels unfair to criticize it for this.
The EHP-O2D is essentially the exact same unit as Epiphany's amplifier without the DAC (EHP-O2). The internals of their DAC only unit (E-DAC) have been squeezed into the EHP-O2 where the batteries used to be. The rear plate has been switched for one that includes a USB connection, which is why the back of the device is the only place you will see the proper model name (EHP-O2D).
The EHP-O2D is a simple, but solidly built unit, with a couple of design nuances that may not impress but the company's philosophy here is all about the sound quality and it shows. The sound is as smooth, airy and detailed as I have experienced from portable USB audio. This is the most expensive portable DAC & headphone amplifier that I've tested so far, but listening to it will almost certainly make you wonder why it doesn't cost even more. It might be a little less versatile because of it's power, but if this is the trade-off you have to make to experience audio quality of this calibre... I will gladly take it. I love this machine and I'm not sure how I'm going to send it back!