Review of the Epiphany Acoustics EHP-O2D Desktop Amp – An Outstanding Amp and DAC

Pros: Sound quality, near perfect transparency, DAC functionalities, driving capabilities, design and look, small size, price
Cons: Power adapter, usb wire length

Build Quality: 10/10
Design & Look: 10/10
Functionalities and ease of use: 10/10
Audio Quality: 10/10
Value: 10/10
My final Rating: 10/10

Purchase Date: September 2012
Purchase Price: £190

I first of all would like to thank Oliver at Epiphany Acoustics for selling me the EHP-O2D at a reduced reviewer discount price. I purchased this Amp/DAC combo after wanting a something better than my soundcard (at the time it was a Asus Xonar D1, which has now been replaced with the Xonar DX on my new 2012 built PC) for my headphones. I did quite a lot of research whilst thinking about DAC combos and the EHP-O2D not only caught my eye due to its capabilities, but also due to the fact that it was built based upon NwAvGuy’s specifications.

The EHP-O2D can be directly purchased from Epiphany Acoustics.

EHP-O2D - Front Facing

To see my initial impressions and my unboxing video – Click here

The EHP came with a simple box, where there was its adapter included (and a black extension cable), a USB cable to connect it up to the PC, a 3.5mm to 3.5mm wire and 4 sets of rubber stickers, that can be affixed at the bottom of your EHP.

EHP-O2D - Package Contents

EHP-O2D - Rubber Pieces

Build Quality

The build quality of the EHP-O2D is brilliant. The internal components are enclosed by a black painted metal surrounding. The front panel has the AC power input, the power switch, the output and input jacks, a gain button/switch and a volume knob, that has grip on it, in order for you to easily turn the volume. At the back of the device, the USB port can be found, where it can be connected to your PC.

EHP-O2D - Front facing

EHP-O2D - Back view with mini USB input

It is also an extremely small device, relatively speaking, which means it can sit anywhere on your desk and not be intrusive, unlike some other desktop amps that are extremely huge.

The build quality is thus top notch, after several months of constant use and even with a few things accidentally dropping on it, not a single scratch nor dent can be seen in sight. It seems to be built to last and to remain a beautifully constructed device on your desk.

I personally also love its look, there’s just something about it that denotes the word “cool”. It just sits there not asking for much attention, but when you do give it some attention, by plugging in your headphones, it will steal your attention extremely well.

EHP-O2D - Dimensions EHP-O2D - Dimensions EHP-O2D - Dimensions


Functionalities and Ease of Use

The functionalities are very simple. You can use the EHP-O2D in two manners:
-As a headphone amplifier, by passing a signal via the input jack and thus through your output jack receiving the amplification.

EHP-O2D - Plugged in EHP-O2D - Input with the MJ2


-As a USB DAC – as this is the “D” version, thus the DAC version, it also sports the USB DAC functionalities which allow it to bypass your soundcard, or on-board sound on any USB DAC capable device (like the Samsung Galaxy S III) and use its internal amp to provide you with a superior music reproduction.

In either mode, the gain can be adjusted from the EHP-O2D itself. When the gain switch is not pressed, it is in low gain mode; however when the button is pressed, it goes into high gain. The volume can be adjusted accordingly in both low and high gain settings, which allows it to be extremely quiet for low level listening and extremely powerful in driving high impedance headphones/earphones, such as the Fischer Audio FA-002W’s. The EHP-O2D, at an audio meet had no problem driving any headphone I threw at it – each and every single headphone was more than loud enough (and that was in a relatively noisy environment) – thus this won’t have any problem driving those extremely high impedance headphones like the Beyerdynamics.

As for the ease of use, it is extremely easy as plugging and playing any USB device. Once plugged in, into my Window XP & 7 PC, my PC picked it up straight away and installed it immediately as ODAC. It was as simple as it sound, there was no drivers to be installed and the EHP-O2D appeared in my Windows sound options.

Overall, the functionalities and ease of use score top marks, as it is simple and intuitive to use and more so functions very well.


Sound Quality

EHP-O2D - Gain Knob

The sound quality is one that is always hard to judge with an amp – but the EHP-O2D made me realise what I’ve been missing all these years, especially via my Asus Xonar soundcard.

The sound that the EHP-O2D provides is almost perfectly transparent and sounds like it adds clarity to your audio. This is something that I had rarely come across before as it made me enjoy my music more than I had done before. This is something I had only ever experienced on the go with my DigiZoid ZO2, however that “fullness” of sound wasn’t exactly transparent and thus the ZO2 had a warm sounding tone to it. The EHP-O2D, in my opinion is in a different league. It produces music so well, that only several hours of listening to it, and then going back to what I used to listen to made me realise how good the O2D was. This also doesn’t only apply with music, but with games as well, such as Battlefield 3 on the PC. I know can hear footsteps, explosions and gun fire at a much clearer and better quality than I could before.

Thus the sound reproduction is almost perfectly transparent, but there is a slight dip in the mids. This wasn’t apparent at first, but after comparing the EHP-O2D to much more expensive amps out there, then I could hear an extremely small dip. This isn’t something one would hear at first, but something that would be heard after VERY CAREFUL analysis of an expensive dedicated amp, versus the O2D. By expensive I’m talking about a £300-1000 dedicated amp (with no DAC functionalities). So, is it perfectly 100% transparent? No, but is it up to 95% transparent? Yes.

This gives you an idea why it is so popular among audiophiles and audio enthusiasts, as at the price point the EHP-O2 comes in, let alone the DAC version, it blows most of its competition straight out the water. More so, it is incredible that at this size, it can amplify, without any sort of distortion (in any frequency) your source. In other words, putting a bass heavy track, then going on high gain, and max volume, causes 0 distortion. In fact I was scared that, that strong signal would blow my headphone’s drivers out, as it was so loud, but yet so clear and transparent, that it completely made my jaw drop. Normally amps at that sort of volume would start distorting at some point, be it in the bass or treble – but this amp, wasn’t having any of that distortion business, and provided a clear reproduction at any given volume.

EHP-O2D - USB DAC mode

Now going into the DAC functionalities, as you can probably imagine from my description above, that it destroys my Asus Xonar D1/DX – that would be an assumption of yours, but a very precise one. I feel sorry for myself, for listening all these years to my headphones and earphones, either through my Asus Xonar D1/DX or my Logitech Z-5500 headphone jack (which in turn is plugged into the soundcard). I can’t listen to my music via my headphones without it going through the EHP-O2D and more so all I need to do is a quick flick of default devices in my Windows sound properties, and I’m in audio bliss with the O2D. I absolutely love listening to my music at night and sometimes put on the excuse in my head saying: “It is late at night, maybe I shouldn’t disturb anyone 9dispite it actually not being late, and everyone awake) and thus I’ll listen to my Denon AH-D2000’s with my EHP-O2D!”

Overall, what can be said of the audio quality you are receiving, is close to audio perfection. At this price point, with this device, I can’t see anyone complaining for any given reason. A solid 10/10 (something I have almost never give, unless it is exceptional), to a very much worthy device constructed by Oliver at Epiphany Acoustics.

Conclusions and final thoughts

The question here is, why are you still reading? Go out and buy yourself one, just like I did. Seriously it’s worth it. If I haven’t made that clear enough in this review, then I can’t quite emphasise my love for this device in words.
I utterly enjoy using this device, but not only because of its sound traits, but its overall package. The look and feel, the small design, the easy functionalities, and last but not least Oliver himself at Epiphany Acoustics, who provides very fast and friendly customer support (something that in fact is rarely found these days).

The only thing I can think to critique the package received is the overly large WHITE power adapter  I would have preferred it being black, but that doesn’t really matter as it isn’t seen (as you can use the power extender), and the USB cable being a little on the short side for me, which again is being extremely picky, as one can easily change the cable!

Top marks to Oliver and his company Epiphany Acoustics for providing us in the EU and the UK a fabulous product!

Hope you enjoyed my review!

23 thoughts on “Review of the Epiphany Acoustics EHP-O2D Desktop Amp – An Outstanding Amp and DAC

  1. John Hutchinson

    I have looked at this amp/DAC in relation to providing a headphone out for my new hifi amp, which doesn’t have a socket.

    The thing that puts me off and also off the headphone amp on its own, is that it seems to be for computer file replay… Not running off the line out from my main amp.

    So, I will probably go for a Schiit Lyr or HiFiMan EF5 or similar.

    1. TotallydubbedHD Post author

      I don’t quite get how you are connecting your hifi amp to an amp – and the reasoning behind it.
      If all you need is an amp – as you have your hifi amp doing the “ground work” I would look for something with an optical connection.

  2. Albert

    Good afternoon gentleman.
    I have some doubts about what relates to this amp (02 + ODAC), I live in Mexico, JDS labs, would be the option to consider, however JDS handles other features for the switch gain (2.5x low / high 6.5), however your “epiphany” handles (1x low / high 2.5) correct?, that the difference between these gains? how about this amp / Dac, for some sennheiser hd 650?, also I have a sony xba 4 8ohms, they also could be connected?
    Thanks and greetings from Mexico

  3. SaL

    Great review. Highly tempted by this.

    I take it you get Dolby Headphone surround out via the Xonar’s RCA/line out to the 02D? The same firm is working on a SPDIF option… do you think it better to wait?

    Again thanks – superb site btw.

    1. TotallydubbedHD Post author

      Cheers for the comment.
      Don’t quite understand what you mean by the SPDIF.
      I used line out of the DX to my Logitech Z5500 and I used the O2D via USB DAC to my headphones only.

      1. SaL

        Thanks for replying 🙂

        O2 are, if I’m not mistaken, may well produce a very similar DAC/AMP with a SPDIF input.

        Have you ever used Dolby Headphone surround out via the Xonar’s RCA/line out at all for games (bypassing the 02D’s DAC and just using the amplifier)? For stereo music using the external DAC I assume all you’d need to do is click on the output in the Windows Sound Panel = awesome sound?

        1. TotallydubbedHD Post author

          O2 nor the O2D have optical in or out. Maybe another version does, but not those two – that’s for certain.
          I also have TESTED dolby headphone, and found it utterly useless. Like a gimmick so to speak. Much prefer my O2D + D2K’s vs my DX + D2K’s with or without any sort of enhancements that Asus provide.

          And yes, all done via Windows – really simple really.

  4. SaL

    Aargh! My command of English! Meant to say that they are planning on a future release with SPDIF based on the existing range. My bad.

    Dolby Headphone..I find it works very well for gaming and movies – but not music (In that case I would switch to the USB mode for stereo as you suggested above). I’d really like to know however if Dolby Headphone *actually* works well from the line out of the soundcard to the amp in the O2D, solely for the surround DSP?

    many thanks TotallydubbedHD

    1. TotallydubbedHD Post author

      Ah no idea haven’t tried – I don’t have my headphones ever connected via O2D via my DX.
      I just don’t see the point in doing so.
      However to be the good man that I am – I plugged in a 3.5mm wire from my DX to my O2D (unplugged the USB) and changed the input to headphone from 6 channels and then clicked on the dolby headphone sign – yes it works.
      But as stated before, just makes it sound bad – just spaces out the sound, making you lose a LOT of detail (mids mainly) and that upper end sparkle – this is testing with MUSIC.
      FYI on my DX I’m running C-panel uni-drivers – but the same principle applies with the Xonar utility.
      So yes, in short: Dolby headphone WORKS with analogue + O2D + D2K 🙂

      1. SaL

        TotallydubbedHD – TY for answering – huge respect 🙂 Thanks for experimenting with your setup.

        You’re not a gamer then! Games and music are where DH shines, not music. Did you really need to unplug your USB?? .. wouldn’t changing the output device in the Windows sound mixer/control panel alone have done the same thing?… only thinking about ease of use.

        Anyway.. many thanks for answering my questions. Am really enjoying researching what kit to get; and too love stumbling upon sites like yours that love sound and music.

        1. TotallydubbedHD Post author

          I didn’t have to unplug the usb, in fact I didn’t have to chance anything, apart from plugging in the analogue wire into the 02d. The reason I unplugged the usb is to be 100% sure there was no interference or it switching to the dac.
          Regardless, if you have the ehp playing via usb mode, and suddenly plug in something via analogue it well redirect the sound automatically. Glad you like my site!

  5. Neo


    I’m looking for a suitable USB amp/dac for Beyers 770 Pro, 250 ohm version, and this amp/dac is on my list.
    Will it be powerful enough to drive them for a variety of music genres? I guess I’ll always have to use it in high gain mode?

    Thank you, nice review!

    1. TotallydubbedHD Post author

      Indeed these will be more than powerful to power your 250ohm or even 600ohm headphones.
      You’ll be more likely to want to use high gain, but you’ll find that low gain and low volume will also be very loud. Depends on your hearing and preference of volume, but believe me, high gain will be more than enough and have no distortion whilst at loud volumes 🙂

  6. HeGe

    Hello. Great review. I’m really considering to buy this amp to use with my Sony Walkman Z with line out dock and in ear monitors that have impedance around 25 and sensitivity at 500 about 113. What do you think, would it be a good pairing?

    1. TotallydubbedHD Post author

      The ODAC really pairs well with all types of sensitivity and impedance earphones and headphones.
      I’ve paired them with the TBA-04 earphones (which are a little sensitive) and even powered 350ohms headphones.
      So I wouldn’t worry about it!

      If you’re in fact interested in the amp -I have the exact one in the review for sale – as I’ve moved to a full-blown receiver now.

  7. Mike

    I see you rate this amp very highly indeed but are now selling it and have “moved to a full-blown receiver now” — I’m not sure what that means, please could you give details of the make model and reason for your change.

    1. TotallydubbedHD Post author

      Hi there Mike,

      Very easy to answer this: My Denon AVR-X500 takes up quite some space. However I went from having a soundcard -> Logitech Z5500 to a recevier -> 5 passive speakers.
      Thus the receiver is now the hub of everything. I used to listen to everything via my Z5500 and via my headphones, the souncard and/or the Z5500 digitizer sounded horrible. Thus, where I thought to purchase the EHP-O2D.
      The O2D, absolutely blew away the previous alternatives. Despite my soundcard being “good”, it wasn’t as good as the O2D.
      Then came my purchase of the X500, which made me A/B test its headphone output and the O2D’s. I really couldn’t tell the difference between the two. In fact my X500 was able to drive headphones much more than the O2D would have been able to – and in terms of convinience, I didn’t have to change any sort of sound output on Windows, as the sound was going via optical.
      Long story short: The O2D performs just as well as my X500 amplifier does, but comes in at a pocket-friendly size, vs a 10KG amp on my desk. However, on-the-go, I use my DigiZoid ZO2 amp and nothing else. So I have no need for my O2D now. It quite literally is sitting my my drawers collecting dust.

      If form factor isn’t an issue, then you can easily get yourself a full-blown amp that will perform like the O2D, in terms of transparency, driving ability and all at a cheaper price.
      However if, like me in the past, space is an issue, then the O2D is really a no brainer.

      Hope that answers your question fully and truly.
      Any more questions, feel free to ask!


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