Hi everyone, Before I start the review, I would like to thank Fiio for making this awesome DAP at an affordable price and rich features, and also to @Fiio for organizing the tour.
This review will focus on the sound quality and not so much about other aspects, so I'll make the other sections as brief as possible.
INTRODUCTION
I'm an Indonesian working as a Web/PHP Developer in Melbourne, Australia.
Other than programming/coding, listening to music is another one of my hobby.
When I start my headphone hobby, music listening has been a very rewarding experience for me and has helped me in many aspects of life other than music enjoyment, although, with the booming price of high end headphones/IEM, etc at the moment, it has become a bit of a heavy hit on my wallet
Starting from almost 2 years ago I've been really hooked in metal music, and nowadays my everyday music listening always incorporate metal tracks, I guess you can call me a Metalhead but I don't know about that, I also listen to other genres occasionally.
I don't actually listen to all kinds of music, lets say for example Classical, therefore it is important to understand that this review is based on my observation on the kinds of musics I like, and those are mainly:
- Metal (many kinds, mainly the extreme kind, everyday anytime anywhere)
- Rock (mostly Porcupine Tree, Steven Wilson, Radiohead or something like it)
- Pop (90s stuff, rarely)
- EDM (Mostly trance and it's sub-genres)
- Jazz (Norah Jones, Diana Krall and the likes)
- Indonesian Song (it's basically the Indonesian version of pop or rock, guitar is used all the time, sounds natural and relaxing, however, mastering of the song is not very good, this is good to test how good a headphone/Iem handle poorly recorded material)
- KPOP
- JPOP and JROCK/Visual Kei, whatever you call it (mostly the older stuff)
I used the Fiio X7 II for about 2 weeks not including transit times, everyday at work and at home on weekend, I will also make some comparisons to my other gears that i have.
I only use the unit in SE mode as I don't have a connector with 2.5mm balance to be used together with the fiio for my headphones.
EQUIPMENT USED FOR REVIEW/COMPARISON WITH THE DAP
- Shozy Stardust
- Meze 99 Classic
- Sony MDR Z1R
- Focal Utopia
- Chord Mojo
- Cavalli Liquid Carbon (X7 II as DAC)
PACKAGING
the box is black with black cover with the picture of the player itself, opening the box you are greated with the player nicely guarded with thick foam at the top and the accessories at the bottom.
ACCESSORIES
Silicone case
Leather case
USB cable
Coaxial cable
MicroSd pin
Screwdriver for the amp unit
Spare sideguard for the amp unit
Pamphlets and documentation
The Fiio X7 II
The Build Quality is very nice, and also clean, nice colouring for the unit with sturdy construction, unfortunately the X7 II will only be available in silver colour unlike it's little sibling.
This is due to the amp module being silver in colour, so having different colour on the player will not match aesthetically.
It is a little thick, but not overly so and still comfortable on my side pocket.
Nice screen with good brightness to be used outdoor very easily.
All the button are nice and tactile although some accidental click has happened while in my pocket
Some minus point include some mismatch in color at the back of the unit where there is a grayish pannel, possibly for better bluetooth reception.
There is no option to turn off the blue lighting.
At the top of the unit there is the power button and combo Line/Coax/Opt out.
At the bottom of the player you got some socket to connect to the amp unit and at the bottom of the amp unit(AM3) is the micro USB port for charging and data transfer duties, I'm a little disappointed that Fiio does not use USB C here, hopefully this will be rectified for future release.
Other than that you will find 3.5 SE jack and 2.5 balance jack.
On the right, You will find 2 Micro Sd slots which is super nice and is probably one of the best features of the unit.
On the left is the play/pause button and also next and previous button, and also the volume wheel that has a satisfying click when you operate it.
The player itself is very responsive to touch, just like the X5 III, it is snappy enough, although some lag is still there and is subject for improvement in the next iteration.
UI & FEATURES
At the home screen, you will find your usual android interface here, you can find menus and apps such as clocks, gallery, internet, etc and some Fiio specific apps such as the Fiio Market and Fiio Music Player itself.
There are 5 Navigation modes available:
- Folder
- Artist
- Songs
- Genre
- Playlist
For other navigation except folder, you need to scan your library first for it to work.
I'm a big fan of Folder navigation since I like to group all my musics in folders based on my preference, I normally listen to music album by album, so It is very good that Fiio has included this feature in my opinion.
You can then access you on-board memory or to your sdcards(2) to play your music, for some reason the second slot takes longer to load, so put all your favorite music in the first slot as it is always ready.
You can also change the setting in the device, such as wifi, bluetooth, brightness, etc.
On the audio side, you can adjust gain and balance, filter mode, output mode, etc. This is also accessible in the music player itself.
Other than the standard stuff, Fiio has also supplied the unit with Viper Effect, although i didn't use it.
The Output mode is smart, the moment you plug in your cable to the combo jack, it will know what connection is being used, although I only use it in line-out to my LC.
Battery Life
In my opinion the battery life is one of the sacrifice of using desktop class DAC in a portable solution, I found the battery life to be ok at best, although it is not the worse thing ever since it supports quick charge, but in the events where you forgot to charge over night, it may be abit hard to have music ready for the rest of that day until you find a charging socket.
Some bugs/querks/annoyance of the unit
I found some bugs trough my use of over 2 weeks, here they are:
1. The screen sometime freeze while you're swiping around in the folder mode while the music is playing, it will be stuck like that for like 5-7 seconds that it will work again.
2. the play/pause button sometimes does not work properly when pausing, instead it replays the current song.
3. There was 1 time where the music stops half way and then skip to the next track.
4. There was 1 time where the music app auto quit/crash while playing music.
5. the blue light can't be turn off
6. the unit runs really warm sometimes, it can get a little uncomfortable in your pocket.
Sound Quality
The Signatures
The Fiio X7 II is neutral, I would say with just a slight touch of warm to the low frequencies, very slight though, chord mojo is quite a bit warmer than this, but people say that it is only slightly on the warm side, so I hope you get the picture here.
The Bass
The Bass has a very slight emphasis to it in my opinion, but I like it, the drums is still tight and has excellent body, it never ever sounds thin, however you can definitely hear the texture of every hits, it is detailed but does not sound too clinical and instead it has the fun factor, the musicality is there and combines very well with all the capabilities of detail extraction that goes deep, to top it off the resolving ability of the Dap is top notch too, in avery fast blastbeats drum hits, it sounds distinct and fast and it has never sound like the notes are diffuse together, this is bass done right, Fiio has always impart some warm to it's product, but the tuning this time is the best implementation so far from all their products I have heard.
The Mids
The mids is detailed, resolving and articulate sounding, it has just the right combination of body in it's tone, not too think and not too thin, therefore it is very easy to make out what the lyrics is in a song, as the syllables are very clear sounding.
In Metal music, Shriek, Scream and Growl vocal technic is a norm, it's often hard to understand what's being said, and for this type of vocals the X7 II shines, the articulation is in effects here, it is easier to hear the lyrics and also the bites, raspiness, and coarseness of the vocals is full on, you can hear the crackle of the vocalist really clearly without sounding sharp, even some Black metal track that I tried that I know has some sharp shrieking to it sounds more bearable in this, very good performance here.
For femail vocals, it is very sweet, again as a Metalhead i use one of my metal collection to test this out, This time Lisa Johanson from Draconian, She just sounds so smooth and sweet, the timbre is emotional in a sad song, it makes me feel a little sad sometimes, but it's very enjoyable to me as it makes me feel something.
Another case for clean vocals, this for Male is Steven Wilson, In "Drive home" track, he sounds so emotional but relax at the same time, it makes me feel good and relaxed too and just enjoy the music, until the emotional guitar solo in the middle of the track presents the climax of sorrowful and anguish emotion that sounds like the guitar is crying, suddenly the relaxedness is change to something else entirely, and this is a good thing.
The guitars is another part where the X7 II shines, the bites of the electric guitars is strong and full, you can hear the sound change from the time the player picks the string until it fades away, the notes lingers well and the decay is there and present, it's really easy to spot the deacy amidst of what is happening in the tracks.
The Treble
The treble is smooth and sparkly, detailed and generally, the least forward frequency in the sound presentation, it is not rolled off or toned down at all, the bass and mids is just more prominent and more forward.
The tizz in cymbal hits is smooth and has nice decay, it lingers and fades very naturally and there is no sharpness to it.
The DAC in use is Es9028PRO which is a Sabre DAC, Sabre DAC has some specific characteristics to it that can sound glare-ry at times, however I have not heard one here, it just sounds natural and energetic, exist when called open and execute superbly.
I found the treble to be Dynamic in it's presentation, generally it is not as forward as the bass and mids, however often time in the climax of the song where it employs the cymbals a lot, i found it to step forward to balance out the other frequencies, this is very enjoyable and helps maintain the atmosphere of the tracks, when it's calm and solemn it does not offend, when it's lively it's energetic and full of energy.
The Soundstage, Imaging and separations
The soundstage presentation is good, the airiness combined with black background gives it a spacious feeling as if there are some empty space between each instruments, i found it to have similar width, depth and height, so it's quite spherical and is not the wide x-axis type, which is my preference.
Pairing
Shozy Stardust earbud
The stardust has an excellent synergy with the X7 II, the bass hits are tight and the mids are detailed and musical, treble is smooth and sweet and not fatigueing.
Soundstage is good and airy, the treble dynamic certainly helps the Shozy abit here as it is a little rolled off.
Meze 99 Classics
This is an excellent pairing, the 99 classic is a bassy headphone, theoretically a neutral source with heaps of details will be an excellent pairing, which is the case here. The Meze is warm and sweet but can sound a little muddy on the vocals for some tracks, the Clarity and articulation of The X7 II helps a lot here, I found the vocal more resolving and more articulate, while the bass controlled, the treble sttill retains the original signature of the headphone a slight roll off at the top fo fatigue free listening.
The meze can be modded to support balance connection fairly easily, this will be interesting to try.
For people that does not like IEM, this will be a good option.
Sony MDR-Z1R
The Z1R is not a hard headphone to drive The X7 II has enough power to drive it fully without external amplification, I found the Z1R retains much of it's qualities and signatures without moch change. What can be noticed though is the detail and articulation prowess of the source feeding it, The bass has it's signature boost down low while being controlled, Mids still has good body, sweet and relaxed laid back feeling.
Overall the X7 II drives the Z1R excellently.
Focal Utopia
Another High-End headphone that is not hard to drive, just like the Z1R, I found the Focal Utopia to be fully driven from the X7 II, Soundstage is intimate but spherical, Vocal is clear, articulate and is vivid and is extremely detailed, Bass is controlled and tight with very fast speed, Treble is detailed, smooth and just want to please, there is no harshness and sibilant, everything is there and I found this pairing to be an excellent one.
AS DAC
Cavalli Liquid Carbon (X7 II -> LC) vs (Mojo -> LC)
As DAC, The X7 II is more of a neutral source, with very minimal coloration to it and relies on it's technical capabilities to resolve the music, compared to the mojo->Lc combo, the mojo combo sounds thicker and warmer, more body down low, while the X7 II is thinner and less body, and more focused on exposing the details compared to the full on pleasing nature + detail of the mojo->LC combo.
I actually think that the X7 II -> LC combo is more to my liking, as the LC itself is already warm, and the mojo -> is even more warm which can be bad sometimes.
Comparisons
Chord Mojo
Other than the Ibasso DX200, the mojo is the other main competitor to the X7 II in my opinion, They are price close to each other, but one is a DAP with DAP's flexibility while the other is a DAC that has a lot of power and can therefore drive more powerful headphone than what the X7 II can.
The question is, which is more important for you? Flexibility or more power?
And then you have to ask, what kind of tonality works for you, do you like warm presentation?
If you have no exact preference to the questions above than it is down to the performance and technicalities.
I'm probably the first person that says this, I think The X7 II is really, really close to the mojo, I'm not even sure, but to my ears the amount of details is about equal in my opinion, and in some situation probably exceed the mojo.
I don't find myself missing anything with The X7 II, everything in my music that I heard in my mojo is there too with the X7 II, there are some difference though.
To try to illustrate the difference, in my opinion The mojo in general is warmer and can be said to sound more analogue compared to the X7 II which is a little more digital if compared side by side, but that warmness in the mojo presents details in a different way than the X7 II, the X7 II presents it as it is there and the detail is trying to appeal to you, like saying "Hey!, I'm here, look at me!" and it feels more noticable, while with the mojo, the detail is there, but you can miss it while your listening to it due to its warm enjoyment, more like saying "Hey! I'm here too if you need me", now if you are a detail person you would want to hear everything, in this case than the X7 II is for you, if you just want to enjoy music without being bothered by it then you go for the mojo.
But then, there is a value proposition to it, in order for the mojo to play music, you either need a PC or phone, so it's not as flexible, and even then you need cable to connect them together, but you may say "ah, wait there is the Poly!", yes, with the poly your mojo is on another level now, it will have a better interface than the X7 II as you are using a phone, you also has more power on tap, virtually capable to drive any headphone there is except the HE-6 and big planars, but then, it will be even more expensive and is in a nother ballpark comparing to the X7 II's price, so in my opinion, The X7 II presents better value while being flexible and has similar if not better performance/general usability result depending on your preference.
Summary
For the price of the DAP, it is a complete deal for me, it sounds great, good portability, ok battery with quick charge, 2 micro sd's, durable build, and great value for money.
I would really recommend this DAP for anyone looking to purchase Hi-Res portable DAP or DAC/AMP combo.
This review will focus on the sound quality and not so much about other aspects, so I'll make the other sections as brief as possible.
INTRODUCTION
I'm an Indonesian working as a Web/PHP Developer in Melbourne, Australia.
Other than programming/coding, listening to music is another one of my hobby.
When I start my headphone hobby, music listening has been a very rewarding experience for me and has helped me in many aspects of life other than music enjoyment, although, with the booming price of high end headphones/IEM, etc at the moment, it has become a bit of a heavy hit on my wallet
Starting from almost 2 years ago I've been really hooked in metal music, and nowadays my everyday music listening always incorporate metal tracks, I guess you can call me a Metalhead but I don't know about that, I also listen to other genres occasionally.
I don't actually listen to all kinds of music, lets say for example Classical, therefore it is important to understand that this review is based on my observation on the kinds of musics I like, and those are mainly:
- Metal (many kinds, mainly the extreme kind, everyday anytime anywhere)
- Rock (mostly Porcupine Tree, Steven Wilson, Radiohead or something like it)
- Pop (90s stuff, rarely)
- EDM (Mostly trance and it's sub-genres)
- Jazz (Norah Jones, Diana Krall and the likes)
- Indonesian Song (it's basically the Indonesian version of pop or rock, guitar is used all the time, sounds natural and relaxing, however, mastering of the song is not very good, this is good to test how good a headphone/Iem handle poorly recorded material)
- KPOP
- JPOP and JROCK/Visual Kei, whatever you call it (mostly the older stuff)
I used the Fiio X7 II for about 2 weeks not including transit times, everyday at work and at home on weekend, I will also make some comparisons to my other gears that i have.
I only use the unit in SE mode as I don't have a connector with 2.5mm balance to be used together with the fiio for my headphones.
EQUIPMENT USED FOR REVIEW/COMPARISON WITH THE DAP
- Shozy Stardust
- Meze 99 Classic
- Sony MDR Z1R
- Focal Utopia
- Chord Mojo
- Cavalli Liquid Carbon (X7 II as DAC)
PACKAGING
the box is black with black cover with the picture of the player itself, opening the box you are greated with the player nicely guarded with thick foam at the top and the accessories at the bottom.
ACCESSORIES
Silicone case
Leather case
USB cable
Coaxial cable
MicroSd pin
Screwdriver for the amp unit
Spare sideguard for the amp unit
Pamphlets and documentation
The Fiio X7 II
The Build Quality is very nice, and also clean, nice colouring for the unit with sturdy construction, unfortunately the X7 II will only be available in silver colour unlike it's little sibling.
This is due to the amp module being silver in colour, so having different colour on the player will not match aesthetically.
It is a little thick, but not overly so and still comfortable on my side pocket.
Nice screen with good brightness to be used outdoor very easily.
All the button are nice and tactile although some accidental click has happened while in my pocket
Some minus point include some mismatch in color at the back of the unit where there is a grayish pannel, possibly for better bluetooth reception.
There is no option to turn off the blue lighting.
At the top of the unit there is the power button and combo Line/Coax/Opt out.
At the bottom of the player you got some socket to connect to the amp unit and at the bottom of the amp unit(AM3) is the micro USB port for charging and data transfer duties, I'm a little disappointed that Fiio does not use USB C here, hopefully this will be rectified for future release.
Other than that you will find 3.5 SE jack and 2.5 balance jack.
On the right, You will find 2 Micro Sd slots which is super nice and is probably one of the best features of the unit.
On the left is the play/pause button and also next and previous button, and also the volume wheel that has a satisfying click when you operate it.
The player itself is very responsive to touch, just like the X5 III, it is snappy enough, although some lag is still there and is subject for improvement in the next iteration.
UI & FEATURES
At the home screen, you will find your usual android interface here, you can find menus and apps such as clocks, gallery, internet, etc and some Fiio specific apps such as the Fiio Market and Fiio Music Player itself.
There are 5 Navigation modes available:
- Folder
- Artist
- Songs
- Genre
- Playlist
For other navigation except folder, you need to scan your library first for it to work.
I'm a big fan of Folder navigation since I like to group all my musics in folders based on my preference, I normally listen to music album by album, so It is very good that Fiio has included this feature in my opinion.
You can then access you on-board memory or to your sdcards(2) to play your music, for some reason the second slot takes longer to load, so put all your favorite music in the first slot as it is always ready.
You can also change the setting in the device, such as wifi, bluetooth, brightness, etc.
On the audio side, you can adjust gain and balance, filter mode, output mode, etc. This is also accessible in the music player itself.
Other than the standard stuff, Fiio has also supplied the unit with Viper Effect, although i didn't use it.
The Output mode is smart, the moment you plug in your cable to the combo jack, it will know what connection is being used, although I only use it in line-out to my LC.
Battery Life
In my opinion the battery life is one of the sacrifice of using desktop class DAC in a portable solution, I found the battery life to be ok at best, although it is not the worse thing ever since it supports quick charge, but in the events where you forgot to charge over night, it may be abit hard to have music ready for the rest of that day until you find a charging socket.
Some bugs/querks/annoyance of the unit
I found some bugs trough my use of over 2 weeks, here they are:
1. The screen sometime freeze while you're swiping around in the folder mode while the music is playing, it will be stuck like that for like 5-7 seconds that it will work again.
2. the play/pause button sometimes does not work properly when pausing, instead it replays the current song.
3. There was 1 time where the music stops half way and then skip to the next track.
4. There was 1 time where the music app auto quit/crash while playing music.
5. the blue light can't be turn off
6. the unit runs really warm sometimes, it can get a little uncomfortable in your pocket.
Sound Quality
The Signatures
The Fiio X7 II is neutral, I would say with just a slight touch of warm to the low frequencies, very slight though, chord mojo is quite a bit warmer than this, but people say that it is only slightly on the warm side, so I hope you get the picture here.
The Bass
The Bass has a very slight emphasis to it in my opinion, but I like it, the drums is still tight and has excellent body, it never ever sounds thin, however you can definitely hear the texture of every hits, it is detailed but does not sound too clinical and instead it has the fun factor, the musicality is there and combines very well with all the capabilities of detail extraction that goes deep, to top it off the resolving ability of the Dap is top notch too, in avery fast blastbeats drum hits, it sounds distinct and fast and it has never sound like the notes are diffuse together, this is bass done right, Fiio has always impart some warm to it's product, but the tuning this time is the best implementation so far from all their products I have heard.
The Mids
The mids is detailed, resolving and articulate sounding, it has just the right combination of body in it's tone, not too think and not too thin, therefore it is very easy to make out what the lyrics is in a song, as the syllables are very clear sounding.
In Metal music, Shriek, Scream and Growl vocal technic is a norm, it's often hard to understand what's being said, and for this type of vocals the X7 II shines, the articulation is in effects here, it is easier to hear the lyrics and also the bites, raspiness, and coarseness of the vocals is full on, you can hear the crackle of the vocalist really clearly without sounding sharp, even some Black metal track that I tried that I know has some sharp shrieking to it sounds more bearable in this, very good performance here.
For femail vocals, it is very sweet, again as a Metalhead i use one of my metal collection to test this out, This time Lisa Johanson from Draconian, She just sounds so smooth and sweet, the timbre is emotional in a sad song, it makes me feel a little sad sometimes, but it's very enjoyable to me as it makes me feel something.
Another case for clean vocals, this for Male is Steven Wilson, In "Drive home" track, he sounds so emotional but relax at the same time, it makes me feel good and relaxed too and just enjoy the music, until the emotional guitar solo in the middle of the track presents the climax of sorrowful and anguish emotion that sounds like the guitar is crying, suddenly the relaxedness is change to something else entirely, and this is a good thing.
The guitars is another part where the X7 II shines, the bites of the electric guitars is strong and full, you can hear the sound change from the time the player picks the string until it fades away, the notes lingers well and the decay is there and present, it's really easy to spot the deacy amidst of what is happening in the tracks.
The Treble
The treble is smooth and sparkly, detailed and generally, the least forward frequency in the sound presentation, it is not rolled off or toned down at all, the bass and mids is just more prominent and more forward.
The tizz in cymbal hits is smooth and has nice decay, it lingers and fades very naturally and there is no sharpness to it.
The DAC in use is Es9028PRO which is a Sabre DAC, Sabre DAC has some specific characteristics to it that can sound glare-ry at times, however I have not heard one here, it just sounds natural and energetic, exist when called open and execute superbly.
I found the treble to be Dynamic in it's presentation, generally it is not as forward as the bass and mids, however often time in the climax of the song where it employs the cymbals a lot, i found it to step forward to balance out the other frequencies, this is very enjoyable and helps maintain the atmosphere of the tracks, when it's calm and solemn it does not offend, when it's lively it's energetic and full of energy.
The Soundstage, Imaging and separations
The soundstage presentation is good, the airiness combined with black background gives it a spacious feeling as if there are some empty space between each instruments, i found it to have similar width, depth and height, so it's quite spherical and is not the wide x-axis type, which is my preference.
Pairing
Shozy Stardust earbud
The stardust has an excellent synergy with the X7 II, the bass hits are tight and the mids are detailed and musical, treble is smooth and sweet and not fatigueing.
Soundstage is good and airy, the treble dynamic certainly helps the Shozy abit here as it is a little rolled off.
Meze 99 Classics
This is an excellent pairing, the 99 classic is a bassy headphone, theoretically a neutral source with heaps of details will be an excellent pairing, which is the case here. The Meze is warm and sweet but can sound a little muddy on the vocals for some tracks, the Clarity and articulation of The X7 II helps a lot here, I found the vocal more resolving and more articulate, while the bass controlled, the treble sttill retains the original signature of the headphone a slight roll off at the top fo fatigue free listening.
The meze can be modded to support balance connection fairly easily, this will be interesting to try.
For people that does not like IEM, this will be a good option.
Sony MDR-Z1R
The Z1R is not a hard headphone to drive The X7 II has enough power to drive it fully without external amplification, I found the Z1R retains much of it's qualities and signatures without moch change. What can be noticed though is the detail and articulation prowess of the source feeding it, The bass has it's signature boost down low while being controlled, Mids still has good body, sweet and relaxed laid back feeling.
Overall the X7 II drives the Z1R excellently.
Focal Utopia
Another High-End headphone that is not hard to drive, just like the Z1R, I found the Focal Utopia to be fully driven from the X7 II, Soundstage is intimate but spherical, Vocal is clear, articulate and is vivid and is extremely detailed, Bass is controlled and tight with very fast speed, Treble is detailed, smooth and just want to please, there is no harshness and sibilant, everything is there and I found this pairing to be an excellent one.
AS DAC
Cavalli Liquid Carbon (X7 II -> LC) vs (Mojo -> LC)
As DAC, The X7 II is more of a neutral source, with very minimal coloration to it and relies on it's technical capabilities to resolve the music, compared to the mojo->Lc combo, the mojo combo sounds thicker and warmer, more body down low, while the X7 II is thinner and less body, and more focused on exposing the details compared to the full on pleasing nature + detail of the mojo->LC combo.
I actually think that the X7 II -> LC combo is more to my liking, as the LC itself is already warm, and the mojo -> is even more warm which can be bad sometimes.
Comparisons
Chord Mojo
Other than the Ibasso DX200, the mojo is the other main competitor to the X7 II in my opinion, They are price close to each other, but one is a DAP with DAP's flexibility while the other is a DAC that has a lot of power and can therefore drive more powerful headphone than what the X7 II can.
The question is, which is more important for you? Flexibility or more power?
And then you have to ask, what kind of tonality works for you, do you like warm presentation?
If you have no exact preference to the questions above than it is down to the performance and technicalities.
I'm probably the first person that says this, I think The X7 II is really, really close to the mojo, I'm not even sure, but to my ears the amount of details is about equal in my opinion, and in some situation probably exceed the mojo.
I don't find myself missing anything with The X7 II, everything in my music that I heard in my mojo is there too with the X7 II, there are some difference though.
To try to illustrate the difference, in my opinion The mojo in general is warmer and can be said to sound more analogue compared to the X7 II which is a little more digital if compared side by side, but that warmness in the mojo presents details in a different way than the X7 II, the X7 II presents it as it is there and the detail is trying to appeal to you, like saying "Hey!, I'm here, look at me!" and it feels more noticable, while with the mojo, the detail is there, but you can miss it while your listening to it due to its warm enjoyment, more like saying "Hey! I'm here too if you need me", now if you are a detail person you would want to hear everything, in this case than the X7 II is for you, if you just want to enjoy music without being bothered by it then you go for the mojo.
But then, there is a value proposition to it, in order for the mojo to play music, you either need a PC or phone, so it's not as flexible, and even then you need cable to connect them together, but you may say "ah, wait there is the Poly!", yes, with the poly your mojo is on another level now, it will have a better interface than the X7 II as you are using a phone, you also has more power on tap, virtually capable to drive any headphone there is except the HE-6 and big planars, but then, it will be even more expensive and is in a nother ballpark comparing to the X7 II's price, so in my opinion, The X7 II presents better value while being flexible and has similar if not better performance/general usability result depending on your preference.
Summary
For the price of the DAP, it is a complete deal for me, it sounds great, good portability, ok battery with quick charge, 2 micro sd's, durable build, and great value for money.
I would really recommend this DAP for anyone looking to purchase Hi-Res portable DAP or DAC/AMP combo.