This review describes version with OPA209, but other ones should perform on par or better and probably without GSM noise issue. The amplifier is powerful enough to drive power hungry headphones such as orthodynamics, but also has very low impedance for balanced armature IEMs.   DAC, while very good, is not the absolute benchmark - but that is to be expected in an integrated device. Opamps can be replaced - they're SO-8 mono versions attached via a DIP-8 adapter. The only actual drawbacks of this amp are related to ergonomics. Especially the...

SE-5 is a true marvel of engineering, one of a few headphones/IEMs I can say brought a new level of detail and presentation to music and is truly high-fidelity, that is directly comparable to live performance given a high quality recording.   Important caveat: many amplifiers and sources (even many dedicated headphone amps) cannot drive SE-5 correctly - very low output impedance is required. As a workaround, an impedance adapter can be used to reduce the impact of this on sound.   When improperly driven, they sound dull and dark due to...

Review is in the review thread here: http://www.head-fi.org/t/568515/hifiman-re272-review/135#post_7845383   Suffice it to say, these IEMs are perfect once equalized. No ifs or buts. Nothing I've ever tried matches these.   Even without the sound is great, if a bit bass lean and slightly forward. Extension is unmatched by any other IEM.   I'd love if the next revision includes a case/pouch (not just jewel case) and inverse channel balanced cable. Hifiman should really provide different tips - the included ones are unusable except the...

See: http://www.head-fi.org/t/564273/the-beyerdynamic-tesla-dt-1350-fan-club/75#post_7792890

This is an old highest end model of entry level headphone line by Sennheiser model, now replaced by the likes of HD 495. Decent headphone for rock and trance. Lacks subbass and has grainy timbre. Definitely not what I'd call neutral, but it keeps the bass/mid/high balance decently for entry level. Extension is ok for an entry level pair. Cable tends to break by all three jacks - however is easy to replace, though the headphone side jacks are rare 2,5mm mono ones.   HD 497 leak a lot of sound and provide very little isolation, so are...

Beyerdynamics DT231 are an entry level model of the well known company. These headphones are supraaural and sport fake velour pads for comfortable, albeit warm, feel. The pads are of course user-replaceable.   Bass is hugely lacking in quantity, while highs on the other hand are boosted in the sparkly 8kHz region resulting in high-slanted sound signature. Detailing and soundstaging are good. Timbre is ok with exception of bass, where it's poor with little impact and texture. Comfort can be bad if you happen to have large ears. After a...

Bass is slightly boosted with a bit of extra warmth thrown in, but nowhere near the amount present in IE8. Mids sound a bit aggresive with some 3.5k boost. Highs are present, though not exactly delicate. Some 6k hump exists. Extension is ok, but the highest lack volume. In general, the response is bass oriented, which is easy to correct with an equalizer. Timbre is a bit fat on this one. Not smooth, but a kind of "substantial", heavy-handed sound with not a lot of microdetail. Comfort is excellent. Isolation is mediocre - the vented design...

These IEMs sport harsh sound, chubby build uncomfortable for smaller ears or ear canals. Due to chubby housings, I couldn't wear them for longer than few hours at a time.   Bass is pretty much lacking, as typical of balanced armature. It simply isn't there. What is there, lacks decay and impact completely. Mids are good quality and quantity. Highs are boosted in 8k region giving them a harsh, sometimes sparkly signature. Extension is not great, ending at 16kHz. Detailing is exaggerated which combined with the sound signature sounds plain...

VSonic GR07 is a great example of IEM strong because it has few flaws and almost all of these are possible to correct with a good equalizer. Bass is perfectly controlled, excellent texture, very well extended (-6 dB at 30 Hz with perfect seal), perhaps a bit warm due to high-bass boost (~250 Hz). No bass bleed is present. Mids can be slightly forward to slightly laid back depending on tips and depth of fit. Highs... here's the issue. With shallow insertion, there can be a fair amount of lower highs boost, around 6kHz, which combined with some...

These are budget-minded basshead's dream come true. Others might not be satisfied by the bottom-slanted sound, which can be hugely improved with equalization, otherwise they sound dark and laid back. The sound is precise, with engaging musical quality to it. Bass is very well controlled despite the amount. Mids are neither forward nor laid back, perhaps slightly boosted in upper registers. Highs are actually well extended, but overshadowed by the huge bass. Brainwavz M2 are very efficient and despite it, don't hiss at all. However, they will pick...