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Epiphany Acoustics EHP-O2

Posted

Pros: Clear sound across the FR, portable(ish - size but battery), drives both IEMs and full size can well. Low noise floor

Cons: you may want RCA-ins when you get it(I did).but portable :D ! Australian wall wart, 2RCA-3.5mm plug and 3.5mm to 3.5mm short interconnects would be g

Pre-Ordered from Oliver (EA) in Oct(?). Received the unit about 2w ago.


The bad
The volume pot tracking is not very smooth (catches a bit on some positions (tactile feel, not audibly)). (will check whether pot knob gets caught on the case) (edit: yep, that's it, no real quality issue there)

To my surprise, the unit does not come with a 2RCA->3.5mm or 3.5mm to 3.5mm .I only had a fairly long and rigid one. I wish Oliver would include at least some cheap interconnects biggrin.gif

I'd probably also like a small manual explaining what not to do. (e.g. will it explode if I leave it plugged in for a weekend at work, and come back on mon to find my building charred. Or does the charging circuit cut off at a certain voltage? does it get powered from AC or via batter when AC is plugged in?), or is pressing the gain button while the unit is on bad or not, etc. How to change the NIMH batteries or something. (and rules of when to charge them for longer life or something. What warranty do we get? What are the return conditions for the warranty claims (who pays shipping where), etc)

I also wish Oliver could source Australian wall warts, but he couldn't at the time. The AC-AC 15v 0.5A adapter with the UK plug is huge. I could only find replacements w the AU plug at Jaycar and Mwave, and they're $30+ shipping ($50...). To be fair, he did give me an option of a small partial refund and me finding my own PSU, but it's probably best to just use the UK one with a socket adapter biggrin.gif

The good
That aside, I've been playing with it for a week now, and the sound is great.
Crips,extended bass and highs, present mids, great perceived soundstage and dynamics.
The low output impedance and the decent max output let me drive my GMP 450 PRO (300ohm, no idea what sensitivity. Sound great at hi-gain/about 3/5 of the vol) and UM Mage (demo)/Shure se425.

Both the IEMs and full size cans sound a lot better than my Musiland MD11 and MD30 - much lower noise floor and perceived sound clarity, fr linearity and bass quality (tales of folksy better extension and depth biggrin.gif go here). I did expect that for the IEMs, since the hp jack on MD11 and 30 is 2-3ohms, but certainly didn't expect that much of a difference for GMP450 PRO. I'm also rather surprised, just how much of a difference a low impedance output makes for IEMs.

For IEMs, O2 also sounds noticeably better than my Cowon d2 portable. (hmph, I might have to start carrying it around biggrin.gif )

The build/case all look and feel very sturdy.

Despite the designer's comparisons to Benchmark DAC, I did not find the sound to be similar (I thought DAC1 was awfully bright, almost serrating, which was not the case with the O2). edit: there is a slight qualification to this, MD11 has slightly rolled off HF as per the RMMA, so YMMV on this a bit, but I don't expect it to become awfully bright on straight (+-0.1db) FR sources.

So...
I wish I bought a desktop version (6.5mm out, 2RCA in) and a portable version biggrin.gif, but Oliver/EA and NwAvGuy did very well.

PS I will be cracking it open next week at home and maybe posting some pics on what's inside (part quality and all, not that NwAvGuy approves biggrin.gif ), tho I'm not sure if there's any point, since the O2 thread probably has some

Posted

Pros: Excellent workmanship and wonderful amp

Cons: I own only one

 

 

When I first read about this amp, I was skeptic about the sincerity of the  measurements at first, but I had to try it myself after his claims. After preordering, it came about  6 weeks later, and what an amp, I just now knew how wonderful this amp is, esp. with my Centrance LX Dacport, they were made for each other.

Music never sounded so good. Natural sounds, beautiful and precise instrument separation, the most important thing is balance nothing overwhelms neither the Bass or the treble, but the mids are really what I enjoy, along with the soundstage, not big but it is there and what a stage! My advice to anyone thinking of getting his first amp, is to make this one on the top of his list.

The nice thing about both the amp and the Dacport LX is the size , where both can be carried in a pc/any bag easily and you can enjoy audiophile quality music anywhere & anytime. The sound you will be getting from these two is phenomenal in respect to their size, price ratio. Thank you Epiphany and thank you Centrance, you made me happy, and that's what is important.

Posted

Pros: Extremely low noise floor, wire-with-gain sound aka you´ll notice new details in songs, made in England, solid build quality

Cons: None at this price, except that it might make you feel bad about some previous purchases, gain even on 1x mode is too high for some sensitive IEMs

What can I say... The amplifier designed by The One Who Cannot Be Named, produced in mass by a new British audio company. I´m not going to cover the design philosophy of the amp as anyone can Google the O2 amplifier page to find out what it´s about. What sums up everything I can say about this particular amp is that I used to own a Benchmark DAC-1 PRE and I´m pretty confident I couldn´t tell it apart from this in a blind test :)

 

If you are looking for an amplifier with intentional coloration/pleasing euphonic sound, look elsewhere though. I don´t think the O2 succeeds in making all intentionally colored amps obsolete - there´s a space for some of them, but for most people I think it just makes more sense to get a neutral source like this and concentrate on buying different kinds of headphones instead. For people new to Head-Fi, you can now get an amazing budget rig by getting this and the EDAC and a good pair of headphones like the Sennheiser HD 600/650. For many it´ll be a very nice end game rig. On the other hand if you´re a more experienced headphone hobbyist there´s no reason not to check out the O2 amplifier (even out of sheer curiosity) as it costs next to nothing compared to what we´re used to paying for our amps.

Posted

Pros: audio & build quality

Cons: Portability & battery life?

Over a period of time I bought a FiiO E5, a CMoy and a FiiO E11, which all raised the soundbar. I bought the O2 because of NwAvGuy's writing.

 

The amp turned up one and a half month late and initially without an AC-AC power supply. But thanks to good communication with Epiphany's Oliver this was not such a very big deal.

 

The O2 drives my Audio-Technica ATH-M50 easily. My iPod touch V4 32GB is connected to the O2 with a simple FiiO line out dock L9 connector. Expensive cables are no longer necessary, I assume because of the high input impedance of the O2. I have attached the iPod to the O2 with 2 pieces of sticky double sided foam tape. I have put an old belt on an old leather bag to carry the two.

 

You notice immediately that the O2 is totally silent when music is not played.But when it plays... I have never heard bass, mid range, treble, sound stage and instrument separation of this quality.

 

Thanx NwAvGuy and Epiphany!!!

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Posted

Pros: Great sound.

Cons: None.

I have mine and it's fabulous. I imagine especially good for harder to drive cans. Better bass, not just more bass, but tighter and better defined. Better 'air' around the instruments, ie, improved separation. Maybe some golden-eared individuals will do a better review. One poster described sibilance and I definitely do not find that with my setup. I used it with my Cowon x7 and the Shure SRH-940, comparing with and without using the outboard amp. This combination has superb synergy. One needs to spend a heap more money to get even more realism from a setup. ( I should add the the Cowon does a great job driving these cans all on it's own, but it's simply better with the amp). As always, YMMV.

Epiphany Acoustics EHP-O2
Description:

EHP-O2 Portable Headphone Amplifier The EHP-O2 is a battery powered, portable headphone amplifier. The electronics have been designed by blogger NwAvGuy. The amplifier measures superlatively and they speak for themselves when describing the quality of the amplifier. This has been achieved by very careful component selection, taking advantage of their specific performance characteristics as well as shrewd electronic engineering. It comes equipped with 2 rechargeable NiMh batteries for portable use as well as an AC adaptor for desktop use and charging purposes. A built in gain switch allows the user to choose the appropriate gain for the source and headphones/earphones being used. The EHP-O2 has: 1 x 3.5mm input jack 1 x 3.5mm output jack 1 x power inlet 1 x gain switch Specifications The electronics in the EHP-O2 were designed to offer superior performance in every key specification possible. A snapshot of the measurements are: THD @ 1kHz: 0.0017% Noise level (ref 400mV): -105dB IMD: 0.001% Power output @ 33Ω : 641mW Crosstalk: 65dB Channel balance 0.6dB Battery life: 8 hours The EHP-O2 portable headphone amplifier is hand built in the UK. DIY Builders: Unassembled PCBs are available for DIYers to build the EHP-O2 themselves.

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