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 ?

Cheers.

Had these Little Gems nearly a year now & felt compelled to give a Review (My opinion) of them.
Best start at the beginning then I guess

Since I 1st seen these a couple of years back I somehow knew I would end up with a pair as looks wise they are indeed Little Gems
Once your box arrives = you'll get the typical Monster Fancy Box & inside that lots of other Fancy Pouches/ cases/ Tips/ SuperTips...
Oh & since it's Miles Davis you'll get a CD & Booklet etc etc...
I cannot fault the Presentation type box & supplied goodies that you get with these Buds, Monster certainly went all out to impress.

After your initial Euphoria wears off & you actually remember you have a set of Buds to try here's where my 1 & only problem started with the Monster Trumpets
There's a lot of supplied Tips/ Gel Supertips & Foam Supertips, but out of them all = I can only use x2 of the supplied Foam style 1's (a dark & a light pair, same Med size I think).
So I've been very carefully swapping around these 2 pairs (trying & succeeding so far) to keep them in good condition, cause I've contacted Monster & hunted high/ low but...
I just cannot see or locate any spare Tips for the strange size of the Trumpet buds ANYWHERE mad:

The above being said = I love these Lil Gems due to the fact that IMHO they sound about %15-20 better than my Monster Turbine Pro Copper's do.
Nice tight well defined Bass, Smooth Mids & very slick Highs & just generally a well rounded type of sound all coming out of these Little Gems

A couple of things to note though & it's these 2 snippets of wisdom =
1 : Save yourself some shrieking messed up highs & ill defined bass by giving them a good BURN IN period, I honestly can't remembers how long it was but it was a while & them Bam their broken in
2 : Good luck finding a snug fitting Tip even out of the generous amount supplied by Monster, I was at 1 point thinking nothing was going to provide a decent seal, so check/ try all

After your Tips of choice are found & your Trumpet's are well Broken in = congrats as at some of the cheap prices I've seen them at these days IMHO THEIR A STEAL
A good all rounder, not just for jazz... Even a bit of Rap can sound very acceptable on these little Gems...
& oh yeah, Did I mention they just look so so cool

Now only 1 problem to solve since emailing Monster = was told tough they wouldn't sell a pack of Tips... So any1 know where I can get more tips ?

Hi,
I've been patiently waiting for my 535Ltd's to get a good few hours run in (this includes the stock cable & an upgraded 3rd party cable purchased from eBay, OFC Silver plated copper with Oyaide Plug). I'll just be giving you my thoughts on the 535 reds & try to refrain from too much into towards cable choice etc...

Unboxing ;
The Shure Red's Packaging was nothing special & thus would probably lead you to think there's nothing special inside... Not like say Unboxing something like a set of Monster Miles Davis Trumpet Buds where the packaging is exquisite to say the least... But that's no bad thing as sometimes fancy looking packaging gets your hopes up too much

Contents ;
The 535Ltd's Come with pretty much what you'd expect in the box like your usual sets of small/ medium & large Foam + Silicone Eartips with a yellow Foam tip that seems to fit medium & large sized ears... But in my own personal case after trying them all + a few 3rd party Tips I bought along with the cable upgrade I actually found that the x2 best fitting Eartips for me were made by Westone & I for now use their Foam & Silicone tips in a large size (Pretty weird to me as I'm %99 of the time a medium tip).
Also they come with your airplane adapter + a Volume control adapter + also a jackplug for converting your 3.5' - Full size headphone socket & TBH with you all 3 of these accessories look & feel very cheap as I guess their the same 1's used with even the cheapest of the Shure SE range so because these are their Limited Editions I guess I was expecting better quality accessories but it's certainly not a deal breaker for me.

Included too is I believe a slightly thicker/ better quality cable rather than the basic SE range stock cable which I thought was a step in the right direction after all Special Edition stuff usually is Special because it has better quality versus it's stock base models

Fit ;
These Over Ear style IEM'S fit pretty much perfectly & once you hit upon your chosen Eartips of choice their very easy to put in & take out again as long as you bend the Kevlar to shape round your ears correctly... I HAVE HEARD OF PEOPLE LEAVING NEGATIVE REVIEWS OF THE 535'S SIMPLY BECAUSE THEIR TO DUMB TO FIGURE OUT HOW OVER EAR IEM'S FIT & THATS JUST SAD
As mentioned once you eventually get your best fitting tip = You'll probably be like me & barely notice their even in & I can quite easily fall asleep with them in after a long listening session

Build Quality ;
Shure have learned from previous mistakes you can tell a lot & I mean a lot of though has gone into making these 535Ltd's IMHO Pretty indestructible barring dropping them in front of a steamroller I think these should last you many many years to come as the build quality on the ear pieces is excellent & The cable looks & Feels really really tough so I don't forsee many returns regards the 535's.

Sound Quality ;
Now my own 535Ltd's have only ever been fed on a diet of my Colorfly C4 Pro & Lossless Flacs with the odd 320kbp MP3 thrown in to compare it against.
If you plan on feeding your 535Ltd's on a diet of uncompressed Flacs or Wavs then you'll most definitely not be disappointed you shelled out the big cash for these just Excellent IEM'S as their by far & away the best IEM'S I've ever had the privilege to own/ hear their just Flawless on all 3 ranges & Make me Smile from ear to ear
Now I did notice when trying Mp3's that they can pick up on any bad rip & expose it's weakness with such ease that if your planning on maybe buying these for your eh Ipod then your just wasting your money as you should buy much more cheaper headphones that don't expose MP3's & Compressed files' weaknesses as easily as easily as the 535Ltd's do.

So to some up then ;
These Shure SE 535Ltd's are targeted at users who prefer Quality & by god do they provide Quality in abundance but please save your cash if your plans were to feed them anything other than uncompressed music from a decent source.
1 last thing is that a 3rd party cable can improve sound, but IMHO only slightly as the stock thick grey cable is great in its own rights, so it's just a matter of preference if you upgrade the cable

Hope this review will be of help to potential 535Ltd Buyers out there & accept my apologies for not mentioning all the colours of the rainbow to describe sound LOL.


Thx J.

1st off I bought these so I'm not 1 of those reviewers that get things to keep if they give reviews etc...

To the IEM's then ;
Here in the UK the cheapest price for mine's (control talk version) is about £250 these days I think.
I bought them 2nd hand from a friend, receipt & verified real, but beware that IMHO if you see these too cheap to be true = they will be fakes as Monster headphones are the most copied ever I think.

Now I'm not going to bore you to death with long winded words & so called "Audiophile" terms those kind of people like to use like "has a lovely colour spectrum" = Eh hello we're talking about SOUND here, so my review is pretty straight to the point & doesn't contain any **dophile terms

The IEM'S once you've found the perfect fitting Supertip for them be it a gel or foam pair = Give you exactly what U put into them IMHO.
U use them with an iPod & your not going to really get great results due to the iPods quality, so try & use a decent source is my advice.
My weapon of choice for my Copper Pro's is my Colorfly C4 Pro which will make your copper's sound truly exceptional.
Extreme clarity & very very true to the source, so if your listening to say a CD/ WAV Quality track be it jazz/ pop/ hip hop/ classical etc... You should get a lovely true sound not clouded by any of the 3 ranges at all, as in the bass is nice & tight, the mid is exactly where it should be IN THE MIDDLE & the treble (hi's) again are right up there & @ no time sound overpowering or give any hiss...

Now I have tried a good few headphones in ear, on ear & over ear but I always find myself reaching for these when I want my clearest sound, so all things said & done I guess these IEM'S are exceptional value for money as IMHO they beat a lot of the other big boy brands like your AKG, Sennheiser, Bose & we could go on all night spouting out names/ brands... But I'll stick to my Copper Pro's thank you very much as they just sound so good for their price that they slaughter the competition IMHO...
NOW All the AKG, BOSE ETC... FANBOYS FEEL FREE TO LEAVE YOUR COMMENTS BELOW, but do try & use normal words that describe sound & not the colours of a rainbow please.

In summary I think I've yet to listen to any type of song be it pop or even techno & not think that these sound great
Thx for reading.
Greetz.

BTW I'm from Scotland so I paid £555.00 for mine, not $555.00 THXU


 


1st off lets get this out the way then eh ;


Baterry life isn't great & TBH with you it was never ever going to be great unless they made it bigger by giving it a higher capacity battery making it bigger, so you kind of know this from day 1 that loud amazing sound comes at the cost of battery drain


 


Now where to begin hmmzzz...


FLAC/ WAV Playback is just outstanding with your chosen cans, I'm not going into sound descriptions as each to their own as each have their fav cans, lets just say this then =


This thing has sounded amazing with any Cans I've tried it with & I have tried several to try & find a weakness, but there is none soundwise it's faultless indeed via headphone usage.


 


Add in the fact it's a DAC in it's own right via an in & out spdif or use the spdif in & headphone out to phono even = the thing still sounds amazing.


 


 


I bought mine from Superfi about 6months maybe more ago now & TBH I just still cannot stop listening to it.


I'm so so so glad I bought it & ignored the heavy price tag, because once you listen to it I'm sure like me you'll agree that the quality it kicks out makes that price tag seem low IMHO.


 


Whoever that obsessed chinese guy who demanded it to be built to such a high standard as it was = I salute you sir as by god it still brings a smile to my face getting on to maybe nearly a yr l8rs hehehe


 


 


In closing = Don't let the high price tag put you off people, hell we all pay high prices for hi-fi stuff anyway, think of it as an extension of your expensive Hi-Fi & you'll understand then why it's worth every penny


A MUST HAVE PLAYER IMHO !!!


 


P.S. Make a 64gb MicroSD card bootable formatted in fat32 = it'll work in it too, so mine has 96gb (after the usual loss 89gb or so of space hehehe) EXCELLENT & what's up with some 1 who just joined a Forum posting a review on a Product they think others would like 2 hear about ?
A Nice welcome friendly reply... Sorry I meant a 12yr old school playground sarcastic reply... That's the thing with all Forums U have good guys & gals & then U have well this user with their comments here under my review post made for god only knows why... I feel sorry for your negative outlook on life there but I think the C4 Pro's too good a product to let your wee comment dent it eh ?