This is review of mk 2 version of this amp. I bought it from directly from Burson Australia. 
 
Ordering Experience:
 
Ordering experience was great from Burson. They had a clearance sale going on at that time where it was listed for $400 which is still going now. Product listing showed mk 1 but they sent me mk 2. Extra points for making me happy. I asked them what was shipping cost and they said shipping was included. I thought maybe they will use some cheap shipping method but nope. It was simply best import experience I ever had. They used fedex and amp reached me in a week total. From Australia to India including customs halt which can normally take a month, thanks to superior service by fedex. My guess is it costs Burson around $100 to ship it but they don't make a big deal out of it in their marketing. Understated and classy. I like that. This makes it close to $300 for amp alone, thats close to ifi ican or schiit asgard. You can now probably understand why I called it best value in headfi right now.
 
Build and packaging:
 
Amp is shipped in card bord box with generous foam cutouts to keep amp safe. It includes power cable and rca chords of good enough quality. You can use fancy cables if you like. Power chord is iec type, ones that are used in computers. It has on board power supply and does not use power brick. Build quality is stellar and high quality. Its made out of brushed aluminium thats smooth to touch. Not too big or heavy and you can transport it easily from one room to another or safely in its box if you plan to take it to a meet. It looks great in pictures and in real life its as good as marketing shots we see on burson site. (something I cant say about all products, ahem schiit modi/magni) It comes with 2 inputs on back and 2 gain stages switchable by relays. This makes it feel more upmarket than say dip switches. Burson branding is engraved on front face plate and looks cool. Overall stying of amp is understated and classy. One thing I liked better on mk 1 of this amp is chunky volume knob. On mk 2 they have made it a little small. It works well and rotates smooth though. Allows you to make fine adjustments easily even if you listen to iems. ( something I cannot say about portable amps with hard to rotate volume knobs and aggressive gain stages like my fiio E12.)
 
Sound Quality:
 
SQ wise I consider it worthy of using with high end hps like Sennheiser HD700, say in $800-1000 range. Its an upgrade over entry level solid state amps like ifi ican or O2. When using AKG K550 and Sennheiser HD700 on something like ifi ican, I can't justify spending more on HD700. But on burson, HD700 pulls ahead enough so that it becomes a clear upgrade. By upgrade I mean more fleshed out instruments, more meat around bones. Clearly you get closer to live performance. 
 
On bringing something like Sennheiser HD800 in mix, I feel benefits of using higher end hps diminish slightly. HD800 offer superior resolution but not enough to be a huge upgrade. So if TOTL cans are on your shopping list I suggest you look into its elder sibling Soloist, perhaps. For high end hps (under TOTL hps) this is a perfect match and imo you are not spending disproportionately on your rig either on hps or amps.
 
Or if you have a set of mid fi cans like AKG k550 or philips fidelio X2 that you love and want an amp that brings out all that hp has to offer, this is a good bet.  
 
Tonal Balance:
 
Its transparent as far as I can tell. Presentation is on lighter side. Bass is strong and punchy. Mids are resolved and clear. Highs on hps like HD700/800 are well controlled and not at all harsh. Maybe even brighter cans it will be troublesome but with a well balanced hp like HD 700 (it has some warmth) its a stellar pairing. I also loved it with audeze lcd 3. Excellent drive and bass. Creamy mids and gobs of detail without getting harsh. On ethereal cans like AKG k550 or Beyerdynamic iDX200IE, sound is not harsh but ligher character of hp can make it too crystalline. I prefer to use warmer source when using K550 with it.
 
Overall its transparent enough to allow full character of hp to come out. HD700 sounds even warmer, AKG K550 sounds crystal clear, Sony XBA A1 sounds warm but still clear. Whatever is tuning on your hp it will come out like that.
 
Special note on IEM usage: if you thought iems have no soundstage and too in-your-head feel, try listening to them on burson soloist sl. It makes my $100 Sony XBA A1 sing. Being hybrid iems they dont have great soundstage so I thought. On burson it sounds like full sized hps. Sound comes from in front of you even when IEMs are tucked in your ears. This has increased my respect for IEMs and its those tiny amps that are at fault and not IEMs.
 
Soundstage wise its well layered from front to back. Hps with great soundstage like HD700 will benefit immensely from it. Has more depth than width and pin point front to back layering. Bass has its own layer and brings out multiple bass layers out very well if your hp is capable of it.
 
Value and conclusion:   
 
As I have already said, its exceptional value considering its $400 shipped. And shipping method is best I can have as well. Its performs on high level and together with HD700 is hard to put down combo. My no of hours I listen to music increased after I got burson cause its so hard to put down.
 
 
Special note:
I am including this note on request of Shetzu as he does'nt writes reviews.
I took it to my friends place Mr Aniel goes by handle Shetzu on headfi who used chord mojo to drive his HD800. He instantly ordered one after hearing it and its price to be used as mojo-burson-HD800 rig. That rig is best I have heard. Very transparent, amazing detail on vocals, completely alive image with great microdynamics and detail. To him biggest difference was soundstage that only proper big desktop amps can offer.

Disclaimer : I received Chord Mojo for review purpose from www.headphonezone.in . I would like to thank Raghav Somani and rest of headphonezone.in team for this opportunity. I used it for a week and its already been handed over to next person in que for review purpose. I am not affiliated to either Chord Electronics or headphonezone.in and will try to present my thoughts on mojo in unbiased way as possible.
 
I have broken this review in sub headings of what I wanted to discuss about mojo. I will mostly be discussing about sound quality after introduction and build. Feel free to jump to headings as you please.
 
Introduction
 
Chord mojo is portable battery powered dac/amp that you can use to power your hps. It has excellent connectivity options, all in digital domain 3.5 mm coaxial, optical and usb. Another port is provided for charging mojo. If you happen to own laptop, mobile or a dap with digital out, chances are you can, with right cable and software use it to feed mojo. Accessories that come with mojo are a bit sparse and all you get is usb cable which you most likely already have in desired length. I used fiio x5 classic out of coaxial port to feed mojo and it was mostly flawless experience. It was not a plug and play affair with my android phone like some other portable dacs. I mostly need a software but since I dont plan to use my phone as source, I dont plan to buy software any time soon.
 
I used Sennheiser HD700, AKG K550, Sony XBA A1 for review purpose. It is a mix of hps with different sensitivities and give good idea of mojo's driving prowess. I compared it X5-E12, X5-Ican, X5-Project solstice during review period to see how it stacks up with other portable and desktop systems. I also used it as dac in my system.
 

 
Build
 
Mojo is build out of single block of Aluminum and has a rubbery coating on its entire surface. Its stylish looking hardware with plastic orbs for controlling all its functions. It has 3 orbs for power and volume up and down and is very easy to use. Input selection is automatic with usb taking priority. Its rather on smaller side as you can see in pic, even smaller than fiio x5. Overall it looks tiny and cute but has a robust build. Its orbs rotate in their sockets and I like playing around with it when listening to music.
 
Frequency Response
 
Subjectively to my ears, mojo sounds neutral with warm tilt. Warmth is easily noticeable with my hps. Mids and treble have very smooth transition and I cant pin point where one starts and other ends. Bass impact is good with right hps. Both mid bass and little bit of sub bass is present and it does not tilt too heavily in one direction. Overall sound is smooth from top to bottom with treble showing some wetness and easy to listen to even on sennheiser hd700. Overall frequency response sounds very linear with no peaks or dips noticeable.
 
Dynamics 
 
Dynamics on mojo are top notch. Some of the best I heard. Using hd700 which is also having very good dynamics, I dont think it masks any dynamic shift that mojo is able to unearth. Mojo sticks to the tune of instrument being played with great dynamic clarity and lets you hear all push pull effects between instruments happening onstage. With hd700 having a good depth, it gives you a clear view of entire stage in one glance, such interactions between instruments are very easy to hear. In this sense its a great match.
 
Transient response
 
Mojo has very effortless transient response and sounds very clean. hd700 also has it as a strong point and detail pop out of blackness in stage very smoothly and effortless manner. Instruments fade out again cleanly without disturbing black background at all leaving no trace of noise. This makes the detail pop and more obviously noticeable.
 
Timber
 
Timber on mojo is rich and separates colours of instruments very well. Tone of different instrument is varied and vibrant. I think it has one of best timber I have heard in solid state dacs/amps. My tube amp, project solstice is only piece of equipment that betters it in terms of variation of tone and richness if sound. When I first heard it, X5 sounded poitively dull and lifeless in comparison cause of more traditional solid state sound. After I got used used to mojo's timber it was more even comparison on subjective level. It is very similar to my tube amp in that aspect.
 
Detail 
 
Detail retrieval on mojo is very good with excellent dynamics, both macro and micro, small details in timber and sound of instruments. I think compared to X5, mojo takes listener one step closer to mic feed. However there are no new instruments I could detect. Same no of music strands were present on both. With mojo you get a added sense of clarity and detail on instruments themselves. Tonally both X5 and mojo are neutral with warm tilt. When I compare x5 to its sabre based elder brother fiio x7, I could hear new instruments. Example On a hindi movie song, d se dance from Humpty Sharma ki... its a very busy song with a smattering of tiny little detail, I could hear murmuring in background on both x5 and mojo. On x7 I could clearly hear what they were saying. Overall I think some tiny details get lost on mojo due to warmth compared to focus on clarity on x7. While x7 looses on dynamics and clean transient response.
 
Soundstage
 
Soundstage on mojo is on intimate side. I think my portable rig fiio x5-E12 offers similar size with slightly more width while mojo offers more depth. I was initially disappointed with E12 soundstage but I think its par for the course and this much should be expected from portable gear with full size hps like hd700. All desktop amps I tried had bigger soundstages.
 
Driving power
 
Mojo offers good driving power for variety of cans. I tried following hps to see what it can do
 
Sony XBA A1: Its an entry level hybrid iem in $100 range. Mojo drove it very well with no background noise and excellent detail as iem was able to bring out. I must admit I am not much sensitive to background noise and use and love a tube amp with full sized cans. Overall with average iems and sensitivity of listener mojo should pair well with iems.
 
AKG K550: This is a very easy to drive hp with 32 ohm impedance and 114 db sensitivity. Mojo drove it very well with even frequency response and good detail retrieval. On subjective level, I like pairing warm and very relaxed sounding amps with k550. Otherwise it sounds overly busy and confused. Mojo has warmth but is not particularly relaxed sounding. Thus I prefer Fiio X5-E12 combo for k550 which imo is relaxed and sublime pairing.
 
Sennheiser HD700: This I think is tipping point for mojo where it starts loosing control over drivers a bit. For testing I was listening to Eric Clapton Complete and Fleetwood Mac Best of, my 2 favourite compilations. Eric Clapton sounded sublime with mojo hd700 with detailed guitar solos and overall great music. Upon starting Fleetwood Mac, as you may know, their music has prominent basslines. Both Fleetwood and Mac are bass players with bass guitar and drum. On songs like "Go your own way", bass was a little behind midrange. Not as prominent or grippy. I thought this was character of mojo and switched to Akg k550. Here I found a perfectly balanced sound with prominent bassline and with more detail to boot. I found this to be odd as on all system I tried, hd700 offers more detail. So I concluded mojo has some difficulty in driving hd700 with changing frequency response and slight lack of detail. I think this is odd cause on volume I go till orange colour on orbs for hd700 which is in lower one third of volume range. Also I thought dynamics were excellent.
 
Comparisons
 
In my opinion mojo is a little exotic sounding gear with unique qualities like very clean transient response and excellent dynamic clarity. I compared it with my portable rig X5-E12 as well as ifi ican and project solstice all fed by fiio x5. In all comparisons I found mojo to have same set of strengths and weaknesses. Mojo offers a better holistic presentation with excellent push and pull between instruments and sticks to tune of instrument played best. Best use hps that offer comfortable view over soundstage at a glance instead of very wide stages that let you focus on individual instruments. It also was dynamically very transparent.
In comparison, E12, Ican and solstice take you little in the stage with focus on individual instruments being played. Consequently they offer much relaxed presentation where each note is more spaced and played little more dynamically. All three offer slight better grip over harder to drive cans like hd700 while mojo offers slightly more detail.
 
Conclusion
 
As a portable dac amp at $600, I think mojo is great. It has unique qualities you wont find easily in regular dacs and you can also add an amp to tailor it further to suit your needs or taste. It comes with complete set of connections and can be used in any system. Overall I am very pleased with mojo and urge you to give it a try.

Note: I was part of X7 international tour. I thank Fiio for giving me this opportunity to test and use potentially higher end gear for 10 days time. It is on its way to next member on tour.
 
INTRODUCTION
 
I was very excited to be part of Fiio X7 international tour. However, when I learned it was going to ship with iem module, I was less than thrilled. Being mainly a full sized hp guy, I simply don't have good enough iems to test a dap that sells for $650. However, when I actually received X7 all my worries were laid to rest. IEM module drives full sized easy to drive cans with authority and ease. I used its hp out as well as line out to drive my external amps.
 
 
 

A pic showing gear I used to test and compare X7
 
 
WHAT i EXPECTED vs WHAT i GOT
 
Looking at X7 thread on headfi I see a lot of people expecting fiio to produce an Astell and Kern beater. In what metrics is not clear. To me is X7 is unabashedly fiio. Its quiet clear after reading literature supplied for tour from fiio and using it for 10 days, where main focus was while designing the payer. X7 offers a capable, no compromise built in amp. Its build is great and a step up over X5 but I dont think its the best out there. Curiously its form factor is on a bigger side. I do think to give it all functionality and great amp it has, fiio made it bigger rather than compromising anywhere. This is by no means audio jewellery and it does costs on a higher side, it has sound quality to match it.
 
UI
 
I encourage reader to look elsewhere for in depth look over the UI. I personally listen to albums from back to back and use folder view to find music. So my expectations from UI are very low. In DAP UI I only look for 2 things:
 
Get the Job done.
Is Rock solid.
 
First point is easily achieved as its based on android. I simply choose folder view that shows all folders in memory. From there I simply browse album I want to listen to. No fuss. For second part, I used it for only 10 days and I didnt encountered any hiccups or freeze. I must say fiio's record has been less than stellar. My X5 is behaving differently to scroll wheel inputs over time. It improves with firmware update so the problem is with software.
 
I really wish fiio use software from previous daps wholesale and keep improving the stability of their software. But the rate at which fiio is introducing new daps with brand new uis, I dont think its gonna happen any time soon.  
 
BUILD
 
Fiio did the unthinkable here. Its substantially longer and thicker than X5 which people though was already on bigger side. The build is slightly improved over X5, but when E12 that sells for $130 is build so well, I expected a bigger jump. This aspect goes a long way in showing how well made budget gear is. Looks like diminishing returns is applicable to sound quality as well as build quality here. I do wish unit had round edges for ergonomic grip as well as different texture on back plate. One aspect I loved about it was vibrant, responsive screen, rather close to my smartphone than I expected. Resolution is not very high but I was impressed by big album art on now playing screen.
 
When talking about build, I think I can put up a lot of points like its too big, screen is raised, and screen has black borders around it etc. I personally dont think these aspects will make even slight difference over my purchase decision of an audiophile dap. One audiophile complain I do have is lack of analog volume control wheel. The price point X7 is playing at, I think a proper wheel with good knob feel should be present. 
 
SOUND QUALITY
 
Initially I was sceptical about sabre chip used in dac. Some people have reported about some digital and bright sounding implementations using them. However the amount of warmth X7 has points towards a very nice implementation. It strikes a nice balance between earthy and ethereal sounding. It leans towards clarity in both bass and mids. Treble extension is great and is usable with neutral to warm headphones to my ears. Bright sounding hps do sound too bright to me like my Sennheiser HD700. Mids are meaty, thick, clear and smooth. Bass is reference quality with great clarity. Thickness or thinness depends on instrument being played. Has good presence and not bass light. Goes deep but not like my desktop amp.
 
X7 VS X5 Classic
 
I prefer X5 classic over X5 II. X5 classic has a very analogue sounding treble (maybe a bit shelved down) thats perfect with my hps. Newer fiio gear has different more neutral tuning than their older gear and I think X7 is a direct upgrade over X5II rather than older X5. 
Out of hp out, I dont think there is much competition. Even with iem module, X7 has better authority and more effortless sound with my full sized hps. X7 lets me hear deeper into recordings, more meat around bones. Hp out of X5 sounds thinner in comparison while X7 sounds meaty and resolved, more akin to live performance with less compromises.
Using X5+E12 combination against X7, sound quality battle is very close with perhaps slight edge to stack. X7 on its own sounds effortless, thick and resolved, signs of quality amplification. I think a big size does results in space needed for good implementation as is evident with X7. X5 + E12  sounds slightly more effortless and relaxed. But its a very close call. To note I regard X5+E12 stack very highly and think it paints realistic enough picture of music that I can live with it for very long time.
 
Pitting X7+ E12 vs X5+E12, I think E12 hits performance ceiling with X5, which results in  little improvement when switching to X7. Sound signature wise, their line out has different characteristics and allows me to compare them using same filter (or colouration). Using X5 stack, bass hits harder, depth is almost same but clarity is much better with X7. X7 also sounds more true to source and changes thickness or thinness more dramatically. Mid range is a tie on both. X7 stack is clearer and smoother while X5 stack has more realistic bass weight behind each note. Treble is subdued on X5 while its prominent and extended on X7 stack. Choose depending on your hps and taste. Timber is lot better on X7 stack with X7 highlighting inherent sound qualities and details instruments much better.
 
These characteristics are present with hp out of X7 as well but become more obvious with slight effortlessness of E12. Overall I would say use an external amp with X7 only if its very high quality  or you want a specific colouration like tubes. X5 improves dramatically with E12 but is not the case with X7 as its in built amp is already pretty good.
 
SHOULD YOU BUY ONE?
 
You should buy one if you mainly use flagship level amps and hps/iems. Improvements X7 brings were lot more obvious with hd 700 that with my other gear. Also consider it if you intend to use it without external amp most of the time. However its excellent line out opens potential for even greater things and lets be honest here, who expects manufacturer to cram in amp in that much space that will eke out every last bit of performance on tap from very capable dac? Though I must say fiio did an excellent job in that regards.
I have been using fiio gear for some time and I do think their stuff sounds great. They do make lots of inexpensive gear but that alone does not makes them so popular as there is lot of gear out there thats even more inexpensive. I do find their nicer gear (like X5 and E12 I have) to have a mature sound that I can enjoy for very long time. I think thats why their popularity has stood the test of time. This quality is there in X7 in spades.
 
Thanks for reading!

I wanted to discuss a bit about HD700 today. I wouldnt include graphs or too much technical information. Simply the way I hear them and how I made a system around them as that is very important with HD700. So, lets get started with little details.
 
BUILD AND FINISH
 
HD700 is built very well. All sliding and rotating mechanisms work with a precision that give away its stature as second only to HD800 in Sennheiser food chain. Head band is silicone treated and gives a rubbery texture on touch. Headband padding and earpads are covered in velour that feels a little differently textured from other pads I have tried of same material. Its a bit stiff at first but after a bit of time, it breaks in and becomes soft and comfortable. Ear cups are made by a mixture of plastic and metal parts. Plastic is of nicer variety and feels more dense and stronger on tapping. Overall it looks intriguing and people who see it are left in no doubt its a rather expensive headphone.
 
COMFORT AND ACCESSORIES
 
 Its comfort is very good. When I put it on, all of its weight is distributed on top of my head. As I mentioned, headband padding is a little stiff that allows it to suspend a bit on top rather than put weight on my and ears completely. They have very subtle clamping force that keeps them on head if I lay down on bed, but not not too much to be uncomfortable. Overall all it remains firmly in place no matter how listen to them without uncomfortable clamp or anything. Weight distribution is quiet good. All contact points are covered with velour like material which is very comfortable for long listening sessions. Earpads are sufficiently deep and I can feel AC aor on my ears while wearing them. Perhaps a sign of how open they are.
 
Accessories are rather sparse. It comes in a cardboard box that is pretty big with generous foam cut outs to keep it protected in transit. Apart from that there is only a manual. The cable is removable with 2.5 mm mono plugs on one end and 6.3 mm jack on other. It does'nt come with 6.3 to 3.5 mm adapter so you will have to use your own if you want to plug it into source with 3.5 mm jack. Cable though is nicely made and covered in cloth below y splitter, kinks a lot and still has memory of how it was wrapped when you opened it. Its a bit intrusive in day to day use, and I have to sort the kinks everytime I start using it.
 
SOUND
 
Ok so the important part. I will divide this section into subsections for easy reading.
 
Initial impressions
 
When I originally recieved them, I was using Audinst HUD Mini. Its an entry level dac\amp unit and sounds good for the price. After few hours of burning in, I plugged in HD700 and was not convinced. Treble on HUD mini is not very refined and in just 30 min listeing session, I had to put down hp. It was too fatiguing. For me, simply unlistenable. Now I had two options, either to return HP or build a better setup for it. I obviously decided to do latter, to see if HD700 can sound convincing and enjoyable. Its treble had a bit of ringing to it, so I decided to go for a warm dac. After reading a bit on different threads, I decided to buy Fiio X5 classic and use it as transport and source. Some people were using it with HD800 and it seemed to solve treble issues. Also Sennheisers are known to work well with tube amps. After asking a bit on HD700 thread I decided to go for one of garage 1217 amps. So I am using following system at time of writing this:
 
Fiio X5 classic > Garage 1217 Project Solstice with 6H6N tube > HD700.
 
After Burn in
 
As I learnt from my first tube amp, tubes take a lot of time to settle down and sound their best. I can still detect sound changing from clausterphobic to wide open, mid focussed bass light to bass heavy. But its bigger issues, mainly treble ringing is completely cured with this setup and I can easily listen for hours at a time.
 
Bass
 
HD 700 is very system dependent and dependent on your preferences you can make it sound bass light or bass heavy. Its major characteristics remain same, you can change how much spotlight and space in soundstage it gives to bass frequencies. Bass is round and snappy. Its dynamic and fast. Does not go very deep like my closed back cans but has a bit of mid bass punch. It has good detail. Bassline almost always occupy lower half of soundstage, giving vocals and other instruments space above it. Maybe cause of great imaging I am able to pin point it. It holds nothing back if track allows for it and you use a bass heavy system.
 
Mids
 
On solid state system, generally instuments sound in second layer behind bass and vocals. Not distant but just one step behind. On tubes , everything expands and mids show bloom and are lot more prominant. In both cases mids are detailed, resolved and thick. If you love mids, I doubt you will remain dissatisfies, especially with tube amps. To show detail, it does naturally and does not sound forced. It seems like a higher quality driver with effortless resolution. Midrange is neutral sounding with little warm tilt.
 
Vocals are very lifelike and natural and it takes listener closer to their favourite artist one step. Does not polish them or give extra bite. Vocals are not overly forward and are well integrated with rest of instruments.
 
Treble
 
Treble has substantial presence, but it aids in giving an organic and natural presentation. It is not used as a tool to give perception of a lot of detail, or bite to vocals and guitars. It has sennheiser house sound and treble is not etched. I must warn you though, with a lot of systems, it can be ringing and fatiguing. But this hp only if you are ready to build a setup around it, if needed.
 
Treble is not rolled off and is detailed. Though I must say, tube I am using has little prominance in treble. Also my dac is warmer, so judging treble is a bit harder. But I can say as it is, its neither offensive nor rolled off or vieled. It aides presentation very well.
 
Soundstage and imaging
 
If I were to choose one aspect where a lesser hp can't touch it at all, it would be imaging. Its so pin point and gives cues of where sound is coming from extremely well. Soundstage width is very good. With my system, it gives a feel of 2nd row auditorium. All instruments are very big in size and not distant at all. Also soundstage depth is very good. Some instruments are in your face, while others are a bit distant, resulting in a very convincing presentation. Overall soundstage performance is its strong point, it can sometimes, depending on recording, can sound out of the head as well, as if sound is coming from in front of me.
 
Dynamics and timber
 
Dynamically very alive and give feel of ebb and flow of music really well. Very refined dynamics with lot of steps between loudest and quietest passages.
 
Timber on my system is rich, a little bright. It conveys inherent properties of instruments and vocals very well. 
 
Conclusion
 
It was initially priced at $1000 and I think it performs like a higher end can. Its a definite step up over mid range cans I own or tried. The price I paid for it, I think its a very good value. For some people it can be a bit uninvolving as it tries to mimic the way music sounds in real life, without adding too much colouration. It does an excellent job at that and if you are looking for a hp that sounds natural, neutral, true to recording and music, you should check out Sennheiser HD700.
 
Thanks for reading. 

Disclaimer
 
I would like to thank www.headphonezone.in for review sample. I got to listen to it for just under a week, free of charge. I will try my best to give as unbiased review as possible.
 
Packaging and accessories:
 
Packaging if iem is very high quality. It showcases included accessories very well and makes a great first impression. Literature printed on it is interesting and shows cut out view of iems which is cool. Accessories include everything you might want. A large semi hard carry case is including that holds iems comfortably. Tons of tips are included and chances are you will get a good fit. I found my personal tips to be a little difficult to use as they come out easily. Included tips have good grip on iem nozzles and dont come out as easily. Apart from these, tuning filters, bass, treble and reference which screw on earpiece nozzle are included. I will talk about these in sound section.
 

 

 

 

 
 
Build:
 
This is highlight of this iem. Beautiful steel housing looks as good in real life as in photos. Left and right earpieces has small red and blue plastic inserts, tuning filters have beautiful patterns engraved, cable is rubbery and thick. Strain relief on headphone jack is a long spring which is very effective. 
 
Overall its a luxuriously build IEM and is its one of best aspects.
 
 

 

 

 

 

 

 

 
Sound:
 
These come with 3 filters to tune sound to your liking. With reference filters, sound is a bit warm, lacking a little treble. Bass is not very tight or detailed but impact is adequate. I did not enjoyed it much on reference filter. So I switched to bass filter. Here it keeps everything same, only bass becomes more present, detailed and a bit more extended. Not bass head by any means, but clearly bass improves a lot in quality. With my fiio x5 classic, bass sounded textured but it was a bit slower sounding apparently cause of additional warmth. I preferred this filter with my brighter amp, but still treble was a bit rolled off for my liking. Upon switching to treble filter, it was much better. It keeps rest of sound same as reference filter, just gives a bit energy up top. This filter I found to be best to my liking. To improve it further I changed tips to my personal double flanged rubber that resulted in even better treble extension.
 
So my point is, it offers tons of options to do system matching, which is a good thing as you can use it with virtually any amp and get a good synergy by little mixing and matching.
 
So for listening I settled down of Audinst HUD mini, treble filter, and double flanged rubber tips. So I made it as treble happy as was possible with my equipment, as its quantity was less than what I prefer. With this setup, sound was smooth, easy to listen to. Still did not had too much shine or shimmer. Bass is also a bit rolled off in deepest regions. Mids were a little warm. Vocals and mids were engaging and enjoyable. It tends to blend instruments a little than crisp separation and sounds coherent.
 
Comfort and isolation:
 
These are meant to be used over ear and come with ear guides. I found it a bit hard to use my personal tips as they tend to come out easily. None the less, included tips are plenty and you will probably find a good seal. Once I got used to them, comfort was above average. Isolation was average, not too good but acceptable. 
 
Comparing to Hifiman RE400, I found these to be a little better. But they are under $80. So sound quality to value ratio is not the best out there. I do think sound wise, you can do better with a bit cheaper options. However if you value build quality, attention to detail, accessories and overall package, then its a more level playing field. These are hands down best made iems i have used.

Disclaimer: I would like to thank www.hifinage.com and Fidue for this review sample.I was supposed to keep it for 1 week for evaluation purpose free of charge. I am in no way affiliated to Fidue or www.hifinage.com. I will be writing this review in unbiased way as possible.
 
To save reader's valuable time, I have structured review a little differently than usual.
 
So lets see how it sounds:
 
General: This is first time I am listening to a hybrid design. It comprises of balanced armature and 10 mm woofer dynamic driver. When I had a first listen I was surprised at how crystal clear, completely grain free the sound was. Later when I tried my other dynamic driver earphones, they all had a little grain in their sound. Another aspect I found different from dynamic driver was clean transient response. While listening to Rhythmscape from Bickram Ghosh, its a well recorded disc that has multiple precussion instruments like tabla, drum etc playing against completely black background. Changeover from one instrument to another was very clean on Fidue. I compared it with my dynamic driver earphones/headphones, even my AKG k550 which are technically capable headphones, had some noise. Also the background is completely black on A73.
 
Bass: Bass is round, dynamic, goes deep, is well textured. It certainly makes its presence felt and is not a bass light iem, from headfi standards. Its punchy and satisfying.
 
Mids: Mids are crystal clear as are grain free, a bit smooth than detailed, slightly warm and lush.
 
Treble: Treble is lively, not overly rolled off but is not harsh at all. 
 
Dynamics: Exceptional for this price range. I found sound to be very lively and dynamic.
 
Soundstage: Soundstage is intimate, especially vocals are front and center and rather intimate. Other instruments are laid around vocals and are also intimate. One criticism I have is soundstage does not has lot of depth and layering is not as refined as some of my other headphones. 
Outside of that, if you like me enjoy a rather intimate soundstage than an overly airy one, where you have to squint your eyes to hear any detail, this iem is for you.
 
Instrument separation: Despite of intimate soundstage, instruments are very well defined and separated. I think intimate soundstage with great separation are one of its biggest strength.
 
Overall tonality: A very even handed frequency response. Note edges are rounded, which gives them a little warm, lush presentation. Its lively and dynamic, thus not a very laid back sound. Detail presentation is relaxed, its their to hear but is not shoved in you face. 
 
Comparison with Hifiman RE400:
 
A73 a step up over RE400. It goes deeper in recordings and brings listener a little more closer to music. Outside of that it boosts a similar neutral frequency response as Re400. It does fixes a couple of shortcomings in RE400, A73's bass goes deeper, is more textured. Also sound is more dynamic.
Where RE400 beats it is soundstage depth, it has very refined layering in its price class. RE400 has sharper note edges and is on colder side of neutral. While A73 is on warmer side and rounded edges.
 
A Note on similarity with Sennheiser HD700: When I heard A73 for first time, it instantly reminded me of HD700. I know its unfair to compare two as HD700 was introduced at $1000, but they have some key similarities as far as tonality is concerned. Them being crystal clear grain free sound, even handed frequency response, slightly warm tilt, relaxed detail presentation. Technically A73 can't compete with HD700 but tonally I find similarities. 
 
Now that the sound part is over I will present some mundane information:
 
Fit: Included are 4 tips, S, M, L and double flange. Initially I thought it will be hard to achieve seal with just 4 tips, but surprisingly all 4 offered varying degree of seal. None of them was perfect seal but double flange tips gave me best seal and almost full sound potential. 
 
Isolation: Once music started playing, I had no problem in listening at normal, "at-home" level volumes on my cell phone in metro. So isolation is acceptable.
 
Build quality: Housing seems to be made of 2 parts, one plastic, one metal that is shaped beautifully. Cable seems to be robust, but is not very flexible. Also its non removable and strain relief, though good, not the best I have seen. If you take good care of them, I am sure they will last you a long time. 
 
Accessories: It includes 4 tips, shirt clip and a hard zippered carry case. It is also equipped with single button remote that worked perfectly well with my Sony Xperia smartphone. It could be used for play/pause and also taking calls.
 
Amping: I used Audinst HUD Mini for most of my listening. I also used Sony Xperia SP smartphone. Audinst is mostly neutral sounding dac/amp and has low output impedance so it had no problems in driving them. 
Since its a hybrid design with 20 ohm impedance, I recommend using sources with less than 1 ohm output impedance for optimum results.
 
Value and conclusion:
 
At $150 I thing its well priced. I think as a overall package it offers great value. Though IEM world sees cut throat competition, it does enough to differentiate itself from other dynamic driver offerings and is well worth your consideration.
 

 
 
 
 
 
  

I have been using RE400 for over few months now. these are rather well known and well documented so I will only put stand out points that I think make it unique.

Build:

Light weight, made out of aluminium. Chord is fabric covered below y splitter. above that its plastic. no microphonics if i wear them from above my ears. Otherwise it can be bothersome. Jack is 45 degree. Overall looks solid and mine is working well without problems.

Comfort and isolation:

Comfort is above average. Isolation is great if I use comply tips, otherwise I think its above average. I do need to insert them a fir bit in my ears to get a good seal, more than other IEMs I have used.

Sound:

Two words that best describe the sound is: Tactile and balanced.

Bass is present and slightly lifted thus gives instruments slightly more realistic feel. Bass is Fairly transparent and conveys what was played well enough. Its fairly tight, though I do find sub bass lacking a bit.

Mids are well balanced with bass. Its not a huge soundstage and mids sound rather intimate. Slightly lush, overall maintain neutrality.

Treble is extended and can be delicate or harsh depending on source, with fair amount of resolution. Again nothing alarming, its not a bright sound to my ears.

Amping: Rather strange in amping department (I guess its common with iems). Sounds best out of my PS Vita, a gaming console, compared to my phone or amp. Detail retrieval drops when used with either compared to my other full size hps, that sound best out of amp.

Value: Overall amazing. I has quiet a lot of hype surrounding it. I do think if you factor everything, comfort, accessories, sound, its very good $100 iem. Taken only in terms of sound, will it beat a $200 hp? I don't think so. But I do think its very competent hp for $100 and a great value.

So I very recently started listening to ue6000, so these are early impressions. I must say these very well match my dark sound preferences. I am enjoying these quiet a lot.
 
Build:
 
Very good looking. Though made out of plastic so not very robust construction. Will require good care.
 
Comfort:
 
They are closed back and they do get sweaty. Cups are not very big so pads or inner cloth may touch your ears. Isolation is moderate with out noise cancellation, nothing ground breaking.
 
Sound:
 
I believe they are very well tuned. Bass is slightly thick and not very transparent. But it has good and satisfying impact. Mids are reasonably clear sounding. Slightly thick sounding lower mids affect clarity, but overall good for the price. Its a dark sounding headphone but treble sounds natural and detailed. So no pitfall here in my opinion.
 
Features:
 
They come with lots of nifty features like noise cancellation (haven't used yet as I used them in my room only), removable 3.5 mm to 3.5 mm cable (easiest cable swap I ever made), fold able with slightly padded pouch and a 2 way adapter (to use 2 headphones out of a single source). As well as a nice cardboard box if you want to store them in pouch.  
 
Some comparisons:
 
Sennheiser HD518
 
Both are dark sounding but treble sounds more linear and natural on ue6000. Mids are more clear and detailed on ue6000. Bass is thicker and more textured on HD518. soundstage has better width on HD518 but better depth on ue6000. Also HD518 is open back so sounds lot more airy. HD518 is slightly more dynamic, thus feel bit more transparent of the actual performance. Overall I paid slightly more for ue6000 than HD518, and  believe its worth the difference cause of mid range clarity and detail, as well as more natural treble presentation.
 
AKG K550
 
Very tough fight here. though AKG is priced quiet a bit high so is expected. On AKG, bass is lot more transparent and captures feel of actual performance very well. It goes much deeper as well. ue6000 bass almost feel one note in comparison. Though it has slightly better impact in comparison. Mid range is more forward on AKG and thus sounds richer. Also clarity and detail is much better. AKG also betters ue6000 in soundstage depth, width and imaging. ue6000 is darker sounding so thats one plus (in my books). Also it has better treble definition and detail than akg. Strange, but I find ue6000 to be darker but hasmore detailed treble.
 
Isolation though better on AKG, I find ue6000 more comfortable as they don't make my ears as sweaty.
 
Overall AKG is more dynamic and transparent, proper mid range can compared to portable ue6000.
 
Overall:
 
I believe their sound quality matches the price I paid (in middle of HD518 & K550). So value proposition is very high as all accessories and features are like added bonus.

I have been using AKG K550 for past few weeks and enjoying them pretty well. This is my first foray into mid fi and I think its a solid contender for getting into mid fi sound especially as it has very low barrier for entry (whole setup). I am driving it with Audinst hud mini, entry level dac/amp and it drives it with authority and good clarity.
 
I have been using Sennheiser HD518 extensively, and have auditioned HD595 as well as HD650 before this. So thats my reference point here as HD5XX series is rather popular and what you can expect to get if you go for K550.
 
First some sound signature differences between sennheiser and akg. k550 requires you to be engaged to music instead of being half asleep to enjoy. k550 has this comparatively thin sound that changes very fast according to notes being played, thus conveys note level information with much more clarity. this clarity improves dramatically in hd650 but still k550 is clearer. For me, I need to actively listen to music and be engaged to enjoy k550.
 
So is one inherently better than other? I don't think so. both sounds are usable according to mood. (its not that I am feeling sleepy all the time, so why Sennheiser only collection?)
 
So now about K550. First some observations about K550 that are striking:
 
Great isolation without any clamping pressure whatsoever. No seal issue for me. I would attribute this to ear pad material. Its most certainly is something special that blocks sound very well. It must be in contact with your skin to achieve seal.
 
Very forgiving for low bit rate material. my much lower hd518 is almost un listenable out of phone with lower bit rate tracks as I could see some holes in music. k550 polishes it and makes it listenable, I think. It might have something to do k550 being easy to drive, not sure why it does that.
 
Very clean sound. no grain whatsoever. hud mini is inherently grainy and with grainy old recordings of the old like led zeppelin, it was almost un listenable on hd518. (all three recording, dac/amp, headphone are grainy making too much of it). on k550 its pristine.
 
Now I would describe frequency response a bit:
 
Bass: awesome. Goes very deep, is tight and reasonably textured. Exactly what I wanted.
 
Mids: Rich, detailed, not upfront. very enjoyable.
 
Treble: Now I am terrified of sibilance or bright sound. But k550 sounds exactly like I wanted it to. I don't think its dark sounding, but its got this peculiar way of doing treble. Treble extension is good but detail is very less thus to my ears sounds perfect. (better safe than sorry. won't cut any points here cause of my preference. I am looking for enjoyable headphones than perfect ones).
 
A word on soundstage:
 
Good sized. Its a closed headphone and has good width and depth with that limitation. Most impressive part has to be imaging. Pin point imaging if its present in recording, even if two same instruments are playing, it places them very well in sound stage.
 
Comfort is very good as it exerts very little pressure on head, but as its a sealed design, it gets sweaty. Ear pads don't allow a lot of breathing.
 
Build quality is good mixture of metal and plastic. not built like tanks and I intend to take good care of them. especially i don't want to change alignment of cups and thus affecting seal.
 
All these things make them a worth can but what makes them 5/5 special is, well they are very enjoyable. Even with their relatively thin sound, they have this deep and satisfying bass thus make for a very convincing presentation. Their sound stage is wide but they don't have diffused presentation like my HD518 that renders each component of music completely separate. Instead it presents a good mix of music, instruments often inter lapping but still sounding separate with note level detail, harmonious with each other. If you think about it, that is how you hear music when in a hall with musicians. Not completely separate from each other.

These in ears are as cheap as it gets and you get what you pay for. Though when compared to similarly priced in ears a few things stand out.
 
Build quality and looks are good. It comes with flat, relatively tangle free cord. Also its fairly resistant to micro phonics. It comes with 3 rubber tips, and I could not get perfect seal with any of them. I could hear faint noises. So its decent in that regard.
 
As for sound, its certainly a better option in its price range. Bass is tight and satisfying. Mids are well integrated with bass and nothing of two stand out. Treble is not extended, but I have not heard an earphone in this price that has decent treble extension. It compliments sound well and nothing sounds veiled.
 
I recommend these iems if you want something in that budget.

These cans offer great multilayer-ed sound especially in comparison to entry level headphones. As I am upgrading my gear in a linear fashion, my last cans are HD448 just a step below these.I believe you already have a decent idea of how these cans sound if you frequent here often, for variety sake, I will try to base review in context to my prior experience ie what such an upgrade brings to the table.
 
When I put these for first time, I was disappointed. After plugging in amp, they sounded as muddy as my $10 earbuds. I had heard these cans needed short break in which was absolutely spot on. In less than 10 hrs, sound started taking its place.
 
These cans are clear upgrade over hd448. Sound is 3 dimensional, multilayered, which I believe brings biggest improvement. It enables much better instrument separation, does justice to each one of them and bring in a lot more detail. A higher end can like HD650 may do a better job at doing this, but thats why you pay more for those.  HD650 are described by many as dark cans having great bass, smooth mids and good sound stage when used with right amp.
 
I will use similar adjectives to describe these except these are much more lenient in amp requirement. Sound stage and open sound is a given no matter the source. Though a portable amp must be used. Bass is punchy and mids are well rounded. So I find these to be great all rounders suitable with all genres I tried. Sibilance is  not a problem as these are dark sounding cans.
 
I think I like this sound signature so upgrade path is clearly paved unless I venture around for variety sake.
 
All in all I did'nt gave it a 5 star cause I don't wanna come back and reduce rating after hearing a much better can. 
 
Edit 1: Some observations after extended listening:
 
Moderately diffused presentation: Instruments sound like in a mid sized room and a bit distant. They don't sound close or in your face at all.
 
Slow and laid back: Really good if you listen to them to relax.
 
Smooth, not utterly detailed: Micro details are a bit of mixed bad. Some time they come out note to note, sometime it doesn't. Overall smooth sounding.
 
Tend to hide some instruments when a lot is going on.
 
Black backgrounds on my amp. Good contrast between instruments.
 
Thick sounding and rather natural mid range. Bass is extended but texture varies from song to song.
 
So not an end game headphone but extremely enjoyable. You will love what you hear if you are just enjoying music instead of looking for technicalities.
 
Edit 2:
 
After owning these for 2 years, I have very clear cut use for these hps.
 
Best hps for relaxing. Period. Nothing is better.
 
Why I say that? A no of reasons:
 
1. Relaxed treble. These are some of the darkest hps I have heard. Treble is just enough to give a them a natural and relaxed presentation.
 
2. Diffused airy presentation. Not a focused presentation. Dissipates energy in songs gives a natural presentation.
 
3. No hyper resolution. Sound is grainy, does not have very high resolution. But instruments are well defined, according to price range. imo this contributes to their relaxing character.
 
Now all these aspects may read like negatives to you, it all depends on what you are looking for. I find all these make them ideal for non critical listening.

I am new to headfi and i apologise if review is not very helpful.
 
This entry level dac-amp is quiet a deal from audinst.
 
Disclaimer: I am currently building my rig and have only entry level models, Sennheiser HD448, Audio Technica WS55 to evaluate this amp. I will update this review after using much better cans with it (will probably start a thread as am confused).
 
As one might expect, entry level cans sound almost same regardless source quality. As I found out, this is simply not the case with HD448 and ATH WS55 that I mentioned above. Am using lossless from my laptop to this amp via USB.
 
I would rather not comment on its sound signature as this is my first amp, but I believe all frequencies have received considerable boost is sound quality. Bass is tight and well defined, treble has sparkle and detail, mids are rounded and lush. All this in comparison with my on board sound card and sony discman. All instruments are better separated and are individually well defined.
 
Overall I urge you to try this product if you are using onboard sound or portable device to drive your cans. Its affordable and brings enough to the table so that you can never go back to those sources.
 
One con I would like to mention in comparison to my on board sound card is, it does not sound very open. Instruments are well separated but overall soundstage seems narrow. Will update review with more use.

I am new to headfi and this is my second review. I apologize if its not very helpful.
 
These entry level cans from sennheiser give a good taste of their higher end models have in store. First how they sound.
 
These have very good mid range. Nice lush and full. Treble is slightly rolled off, giving them dark sound signature and slight sennheiser veil. It is present and clear but does not have any sparkle. This gives them a dark sound signature. Good thing is there is absolutely no hissing or sibilance present.
 
Bass is rather interesting. A layer of bass is present that makes its presence known. Its very high quality bass with good clarity and definition, and is probably closer to what it actually sounds like in person. But will definitely disappoint a bass head ( they will probably insult them with an awful compliment). In my opinion, these are rather genre specific and sound great with rock, classical bot not so good with rap, hip-hop or any kind of electronic music with lots of treble, as they are dark sounding. Overall they are pretty neutral sounding, very inoffensive, quiet mellow.
 
Comfort is very good and their sound signature along with comfort encourages long listening sessions.
 
Build quality is good, its mostly made of plastic but is a solid construction and looks good as well. As they are closed back, they do isolate a bit of sound but nothing too impressive.
 
Amping: Recommend a good source, dac and amp if possible as it brings lots more detail.

This is my first review on head-fi. Please excuse if you don't find extensive or very helpful.
 
First I would like to explain sound signature. I am new to this audiophile business and will try to describe sound as best as I can.
 
Headphones have strong and impact full bass, not overpowering, clear mids, not very detailed but decent, clear and detailed treble. I have not heard a lot of headphones that have V shaped sound signature, so can't say if its V shaped but vocals and instruments don't feel recessed or in background.
 
But bass and treble are clear focus of these headphones. Decent treble presence and detail give these a bright character. They are very musical and fun sounding.
 
That said, I personally prefer dark sound. Listening to these for 8 hrs straight is rather fatiguing.
 
They are also quiet stylish but have a hard clamp.Stretching with hand and straightening then for few seconds have made them acceptable in comfort.
 
They are closed back so isolation is pretty good especially when fresh out of box as they are quiet tight.
 
Build quality is quiet good and they do look stylish. But plastic moving parts mean they make squeaking sound when moving your head around.
 
All in all, as they are fun sounding, decently detailed for price,  I recommend them if you need closed design and prefer bright sounding cans.
 
Amping: Recommend a dac and amp if possible. they are designed for portable devices but a lot more detail come out if used wit decent source.