Pros: Sublime Transparent Sound, Price, Build Quality, Adaptability.
Cons: Maybe could have used the source input & PSU inputs at back
1st things 1st I guess ;
I tip my hat to the Guy who Designed the O2 & to JDS Labs also for making it ready built.
Now I don't know the Guy who came up with this O2 Headphone Amp but if I did I would certainly shake his hand.
I don't say this lightly but here it is then ;
This little Headphone AMP is quite simply put the best sounding Headphone AMP I have ever heard, PERIOD !
You add in the fact that I imported it into the UK direct ready built by JDS Labs for just under £100 including a UK PSU for recharging & I guess that possibly makes this little gem then truly the best value for money Hi-Fi component I own including any full Size Hi-Fi components in my Linn/ Musical Fidelity main Rig.
I normally use this paired with my now favourite cans the Shure SE 535 Ltd red's & all I can say is that it's like I'm listening to my big Hi-Fi System through it's Linn speakers & not through a Headphone AMP/ Cans combo
I cannot stress the clarity/ transparency of this little AMP enough, it's just a breath of fresh air in an otherwise "Snakeoil" & Overpriced, Overhyped & quite frankly mostly Junk Headphone Market. If you buy into the "Oh it has to be a brand name for it to sound good & thus cost a plenty style of thinking" then you'll probably never even get to try this little gem as you'll be too busy handing over £1,000 for your branded heap of junk headphone amp that you only bought because you "Like that brand & somehow think that they'll always produce greatness".
I have heard a few shall we say just Higher Priced Headphone AMPS & I won't mention any names as I don't want to even give their brand names any attention whatsoever when I'm talking about the O2 Headphone AMP instead so we'll leave at this statement then regards how it measures up to other Headphone AMPs costing even £1,000+/-'ish range ;
IMHO it wipes the floor with the lot of them !
Sure some maybe have a Remote Control or some maybe claim their made of Diamonddilliam but very very few will even publish their "Data/ Specs/ Info" on their real world performance so read into that what you will.
So performance wise it's hard to beat this little gem.
On practicality etc...
Sure you could use this portable but you'd need big pockets or perhaps even a little bag or backpack if you really wanted to venture into the urban jungle with it.
I personally don't go portable with it since I own a Clorfly C4 Pro & that is an excellent player that needs no amplifier at all as it'll go loud enough to make you deaf
I use my O2 for tapping into my Living room's Linn/ Musical Fidelity Hi-Fi's Streamer for its Flacs/ Wavs & Inet radio rarely
I use it also for tapping into my bedroom System again a Linn/ Musical Fidelity's Streaming source or again rarely Inet radio.
I guess I should add that I use a Custom made Phono to Mini-Jack Solid Silver Litz Cable a friend made for me especially for this purpose (It's about 3.5Metres Long), I would recommend if your the type who looks for weak links in their Hi-Fi chains then perhaps consider your cable & indeed your cable for your Cans too which is again in my case a Silver Custom job.
I find silver to be very transparent compaired to some of the more expensive options out there.
Back to the O2 ;
I tried it with loads of cans & was never disappointed once, as you pretty much get what you throw into the O2, you give it some trance in 1 side then some nice tight bass comes out the other etc... Didn't find any type of music that it didn't do justice with at all.
I'll say this though, if you throw into it a 128kbps MP3 then that's what you'll get at the other end, so in a nutshell feed it well & you'll be rewarded.
Only downside I see to this is that I do think maybe a little redesign so as the inputs are at the back would be nice & perhaps some1 has now done this, but I prefer sound quality over a small flaw in design any day
So to some up then ;
AMAZING VALUE FOR MONEY !!!
Laughs at the bigger boys & their £500+ AMP's IMHO
Buy 1 as you simply won't be disappointed I promise
1 last thing, please no dumb replies with statements of but this £1,000 branded 1 I have is way better as This is just an opinion so don't throw a hissy fit because I think this little gem is great Mkay ?