Quick review of the FiiO X7
This past week I have been playing and experimenting with one of the FiiO X7s that has been out on World-Wide tour recently. Really appreciate the opportunity that Fiio and Joe Bloggs have given some of us lucky Head-Fi'ers to be able to have an extended hands-on preview of the unit, in our own homes with the rest of our regular gear, that is a rare treat and priviledge.
As you probably recall, but I will remind you anyway because it's important ... the X7s went on tour BEFORE they were commercially available thorugh normal retail channels. FiiO was looking for feedback from the kind of consumers who would likely purchase a highish-end DAP, and undoubtedly also hoping for some favorable buzz, but the other side of the coin is that the product wasn't necessarily entirely ready for prime time when the journey began.
Yesterday (I think), firmware version 1.5 was released, which is the 4th firmware update since X7s started touring approx 6 weeks ago. That one I have not installed yet, but that gives you a sense of the pace of fixes and upgrades that FiiO is cranking out.
One of the difficulties a reviewer has, which a potential purchaser also faces, is whether one judges the product based on where it is today, or where you think it will/could get if X number of seemingly easy changes get made, especially in the UI. That's always a tough call, but certainly FiiO's track record suggests they don't release a product and then forget about it.
In this review, I am not going to include pictures, or have an unboxing video, or (intentionally) repeat every comment that other reviewers have already covered well.
-----------------------------------------------------------------------
My special interests and issues in testing the X7:
-----------------------------------------------------------------------
(1) as a "one piece" portable solution. Not interested in a stack of DAP+(DAC/)amp for portable use; BTDT. We're almost in 2016, the technology has moved enough that I am interested in how good a reasonably-priced single box solution can be, but not willing to carry a whole bunch of gear. (Caveat: always will have a phone. So a phone/DAP + amp isn't adding more pocket hardware than a standalone DAP with internal DAC+AMP.) I understand that not all h/ps will be suitable for portable/mobile use, so selection of appropriately matched cans is part of the solution. (And the entire system cannot surpass the capabilities of the transducers that create the physical sound.)
(2) using the X7 as a high-quality desktop source. For a long time, my PC-based playback system was plagued by USB-related issues. Some other new gear (received after the X7 tour sign-up) seems to have helped greatly on that, but still the idea of having a home-quality source that is potentially less prone to USB noise artifacts is very appealing.
(3) I don't have any good IEMs, and so far haven't much liked the feel in my ears of the few I have tried. I primarily use and like full-size headphones. The Oppo PM-3 is my designated "travel" (closed ear) headphone. The initial amp module available for the X7 was reportedly designed primarily for IEMs, so it's clearly not going to be optimal for my personal use preferences. But how much compromise is there? I was keen to find out.
--------------------------------------------------
Observations, notes & comments:
--------------------------------------------------
*---- about me -----*
I've been "serious" about Head-Fi gear for a couple of years. Well, more correctly have recently re-kindled a passion for headphones that started circa 1977 when I spent two weeks pay to buy a pair of brand new, state of the art Stax SR-X Mk IIIheadphones "ear speakers". Which I still have, and still use. But I have a thrifty bent, and have never owned any (other) real TOTL equipment. One of the real exciting things about today's gear, especially h/p gear, is how close to top quality sound we can get for reasonable amounts of money. But I listen to and enjoy music, I don't listen to gear, per se.
*---- Sound Quality ----*
* the IEM amp module of the X7 drives the Oppo PM-3 very well. I never sensed that it was strained, or unmusical, and it probably could have made my ears bleed at full volume. Excellent match. SQ=9/10. Unquestionably way better than my FiiO X1.
* the IEM amp module of the X7 did considerably better than I expected driving a HiFi-Man 400i, on high gain. It clearly didn't have all the power and clarity of my normal desktop amp, a Project Sunrise III, and usually needed volume settings in the 95 to 110 range (of 120), but I would characterize the SQ as "Very Good," which is a 6/10 on my personal semantic anchoring scale. (10=Incredible, 9=outstanding, 8=superior, 7=excellent, etc.) I would not listen to this combo at home much, given better choices to hook-up, but in a hotel room, absolutely.
* paired with a Senn HD-650, which ought to be a poor match-up, it was, predictably, just "Fair." Somewhat muddy and strained. Listenable, but not capable of the elevating or entrancing experiences we are all looking for. Didn't get as loud as I sometimes like to listen. Doubt that I would bother to get one of the future release alternative amp modules to handle the HD-650 better. I love those headphones but they are not closed and just not well suited for travel use; for in-home use, there are better solutions, see the next two notes.
* Lineout: to the Project Sunrise III, driving any of the previously mentioned cans: Outstanding. Got a hiccup a couple of times during the week, which happened when playing 24-192 FLACs when the battery was low (which could have been coincidence), but otherwise flawless.
* Digital out to external DAC, a Schitt Bifrost Multi-Bit. Didn't think I had the connecting cables to test this, but then I realized the FiiO kit had thoughtfully included a suitable adapter for just this purpose. Super Super Super. Used purely as a transport to even better gear, the X7 works beautifully. It's at least as good as my everyday JRMC on Windows PC --> USB connection --> external DAC configuration, and probably better.
*----- UI and physical design ----*
* I mostly used the device in FiiO Pure Music mode. I primarily listen to entire albums, and thus tend to navigate by hierarchical folders. (e.g., $Music/ABC/Bob Marley & The Wailers/2002_Legend....) My tags are probably in decent shape, but I don't rely on them much. Folder navigation worked fine for me. With the hierarchy I use for folders, any album was just two or three steps away.
I am not a highly advanced Android user. It's reasonably likely that there are things the UI does that I did not discover. There's been a lot of criticisms of the UI. Maybe I have low expectations, but I found it functional enough for me, and reasonably intuitive.
* within folders, things were sometimes odd. Double-disk albums often showed Song 1, Song 1, Song 2, Song 2, etc., rather than keeping the two disks separate and in the expected sequential order. JRMC didn't do that for the same albums, so I don't think it's the tags.
* similarly, on some albums with a lot of tunes, the listed order was 1, 11, 12... 20, 21, 2, 3, 4, etc. Since I like to listen to albums from end-to-end, I prefer to hear them in the order the artists and/or producers intended. Again, could be tags, or the lack of them, but JRMC isn't showing or playing the tracks in this order. The X7 was apparently alphabetizing by track name, including an embedded track number, rather than using a "track number" tag. Maybe there's an option to control that.
* Not sure if the X7 currently has a true "random shuffle" mode. If it does, I couldn't figure it out. The default "play all the songs" order seems to be alphabetical by song. I could get that change to something that wasn't pure alphabetical, but it was too clustered by artist to be random. When I'm listening to stuff in random order, I like the idea that the Talking Heads' "Psycho Killer" could come up next ,even if an A-song like "Accidents Will Happen" by Elvis Costello was last up. It annoys me to know that as a P-song, Psycho Killer is, for sure, 1800 songs away. (How hard could it be to load a 60,000 long list of (pseudo-)random numbers into the firmware?)
* in "individual song" mode, there's an index-scale on the right-hand side of the display, from A-Z. Touching that will jump you to that part of the song list, but be patient, it takes a couple of seconds to respond.
* the pause button is just badly placed. As a right-hander, it's precisely where my fingers naturally wrap around when I hold the unit in my hand. If I had a penny for every time I inadvertently hit the pause button, I would be $34.72 richer today than I was last week. Not a deal-breaker, but it is annoying. On the X7 version ii, I hope FiiO flips the buttons, and has the ON and Pause button above the double-rockers on either side, rather than below them.
* the volume scale works well. Not sure that going to 120 is necessary ... although I somewhat enjoyed it in a Spinal Tap "11" kind of way ... but I could always find a Goldilocks volume that was "just right" for the tune, my mood and the 'phones on my head.
* Did I mention the Android UI is MUCH better than the wheel of the X1? The wheel has given me oodles of nuisance and malfunction, this is far superior. One small step for a man, a giant leap for mankind. So to speak.
*--- miscellaneous other stuff ----*
* I mostly played FLACs, the vast majority of my music is ripped or purchased as FLACs. Played up to 24-192 fine.
* DSD - I don't have a lot of music on DSD, but I do have a couple of albums and some demo files from various vendors. DSD64 sounded great, not sure I put any higher-res DSD files on the X7. Not surprisingly, the X7 would not play a 5.1 multichannel DSD file.
* MP3 - beats me. Mostly when I find any of these still hiding in my collection, I just delete them on sight as archaic relicts. Didn't listen to any MP3s with the X7.
* SACD-ISO. Tried two. One played, one didn't, don't know what the difference was.
* WAV/WV. Tried Ennio Morricone's soundtrack to The Good, the Bad and the Ugly, which is just great music for certain moods. My copy is a one-file WAV rip, it didn't play with FiiO Pure Music. I believe it did with Neutron however.
* One of the previous participants on my unit's tour apparently installed Tidal and Neutron, and (kindly or inadvertently, don't know) left Tidal logged in. Saw it in Android mode, touched the icon just to see what would happen, and was surprised when it fired up, made a Wi-fi connection with the home network automatically, and was ready to go. I did play with it for a few hours. (Okay, six hours. Until 3 am Sunday morning.) I don't think the SQ was quite up to onboard FLAC quality, but it was much better than I expected, definitely quite listenable. And so simple even this caveman could do it. Just for funnzies, I did searches for around 50 albums from my "albums I am hunting for" list, some of which could reasonably be described as "obscure." Tidal had about 90% of them. I was quite impressed with CD-quality Tidal, will probably sign-up. Streamed everything live, didn't try any "download now to play later" kinds of things.
* Neutron: played a couple of songs, just to see that it works. Not an app I currently use, and I didn't spend much time trying it out. Seems to have a lot of customization and EQ options. Noticeably lower volume than FiiO's app.
* Speaking of EQ ... don't usually use it, didn't try it at all on the X7.
* Wi-Fi - as previously stated, Tidal brought up Wi-Fi with no fiddling. Somebody else had set it up before me, so I don't know if that was much of a chore. I never experienced any kind of interference or noise using Wi-Fi, which very much surprised me.
* firmware updates - the X7 arrived as 1.0. I downloaded 1.4 as one of the first things I did after receiving the unit, followed FiiO's instructions, and it installed uneventfully. (i.e., Happy-Happy-Happy-Quick.) Never listened to the X7 with any firmware earlier than version 1.4.
* earlier today when the Wi-Fi was turned on, the X7 told me that firmware 1.5 was available and could be installed. I didn't avail myself of that invite ... something for the next person to do, if feedback on the update suggests it's essentially bug-free ... but nevertheless that's a neat capability for the X7 to have. Especially if it goes through a period of regular firmware updates as more capabilities and fixes are added.
* Loaded up a bunch of xmas and "regular people" tunes on a new micro-SD card in preparation for the annual xmas "obligatory 2 day holiday tour around the state to visit various relatives." Was thwarted in my effort to share good music cheer because the X7 and my vehicle (2013 Honda Odyssey) were not able to to find each other to make a BlueTooth connection. Was on the road and didn't get to fiddle with it much. (Unfortunately, I had assumed the BlueTooth would work, and neglected to also bring a line-out cable as a backup. Whoops. Had to listen to the radio, how retro 20th century. Under my reindeer antlers headpiece, I was secretly embarrassed by this technology failure. Fortunately, the wifelette was pre-occupied with hitting the travel schedule.)
* Battery life: I didn't really time it, but from my experience 8-10 hours seems a good guess. And remember, I'm using cans that need more power than IEMs would. That's enough for me, anytime I know I'm going to be unable to recharge for more than 8 hours, I have a number of cheap "recharge your mobile device via USB" batteries I can bring along. (They're a commodity accessory now, $10-$15 for 3000 to 6000 mAh.)
* Recharge via USB --> fast. I'd guess it took less than 2 hrs to go from 6% to 100%, while the X7 was playing.
* USB connection to PC. Worked fine for a while. Plug in the USB cable, and up popped a "Connect in Android mode" screen. But that is not happening now, in either Pure Music or Android mode. Don't know if I inadvertently turned something off on the X7 or on my PC. Regardless, loading tunes onto a card is usually faster for me if I plug the card directly into a card-reader on the PC rather than use a USB cable to an external device anyway, so I generally do not move tunes via a USB cable.
* re-scanning the list of tunes: the X7 took 80 seconds to scan the internal storage and a 128-GB card, and to register 2,930 tracks. I was happy with that. (The track count for that size card is kinda low, because I put a large number of high-rez files on the card for testing purposes, and of course those files tend to be much larger than normal 16/44.1 redbook files.)
* I LOVE that FiiO isn't burdening the X7 with a ton of expensive internal storage. With a card slot, we get essentially unlimited storage capacity, as much as anyone wants to buy, and can purchase whatever size cards offer the best capacity vs price trade-off, any given time. To me, at the moment the 128-GB cards are still the sweet spot. Because the X7 rescans a memory card so fast, swapping a new card in is no big deal. (Unless you drop the old one on the floor of a crowded public transit bus in the dark, etc. Some free advice: don't do that.) Two card slots would be nice, but it's not essential.
*----- bottom line ---*
I like the FiiO X7 a LOT. Even with the IEM amp module, SQ was excellent on full-size headphones that are reasonably well-matched. Super as a transport to desktop gear. No show-stoppers in terms of usability from my point of view. Its functionality with Tidal is making me re-think about the fun and usefulness of wireless streaming, which up to now frankly I had not seen much point to.
Will it rip the guts out of the market for top-end A&K models? Don't know, but it will certainly push them as "a value proposition." Hate that phrase, but it fits here.
How does the X7 compare to other hot new DAPS, such as the Questyle Q1PR, the Onkyo DP-X1, or even the LG-V10 ? Don't know that either, haven't had a chance to play with any of them.
But I would say that if SQ is your #1 consideration, which IMO it certainly should be, then the X7 is most certainly a very serious contender, as is.
This past week I have been playing and experimenting with one of the FiiO X7s that has been out on World-Wide tour recently. Really appreciate the opportunity that Fiio and Joe Bloggs have given some of us lucky Head-Fi'ers to be able to have an extended hands-on preview of the unit, in our own homes with the rest of our regular gear, that is a rare treat and priviledge.
As you probably recall, but I will remind you anyway because it's important ... the X7s went on tour BEFORE they were commercially available thorugh normal retail channels. FiiO was looking for feedback from the kind of consumers who would likely purchase a highish-end DAP, and undoubtedly also hoping for some favorable buzz, but the other side of the coin is that the product wasn't necessarily entirely ready for prime time when the journey began.
Yesterday (I think), firmware version 1.5 was released, which is the 4th firmware update since X7s started touring approx 6 weeks ago. That one I have not installed yet, but that gives you a sense of the pace of fixes and upgrades that FiiO is cranking out.
One of the difficulties a reviewer has, which a potential purchaser also faces, is whether one judges the product based on where it is today, or where you think it will/could get if X number of seemingly easy changes get made, especially in the UI. That's always a tough call, but certainly FiiO's track record suggests they don't release a product and then forget about it.
In this review, I am not going to include pictures, or have an unboxing video, or (intentionally) repeat every comment that other reviewers have already covered well.
-----------------------------------------------------------------------
My special interests and issues in testing the X7:
-----------------------------------------------------------------------
(1) as a "one piece" portable solution. Not interested in a stack of DAP+(DAC/)amp for portable use; BTDT. We're almost in 2016, the technology has moved enough that I am interested in how good a reasonably-priced single box solution can be, but not willing to carry a whole bunch of gear. (Caveat: always will have a phone. So a phone/DAP + amp isn't adding more pocket hardware than a standalone DAP with internal DAC+AMP.) I understand that not all h/ps will be suitable for portable/mobile use, so selection of appropriately matched cans is part of the solution. (And the entire system cannot surpass the capabilities of the transducers that create the physical sound.)
(2) using the X7 as a high-quality desktop source. For a long time, my PC-based playback system was plagued by USB-related issues. Some other new gear (received after the X7 tour sign-up) seems to have helped greatly on that, but still the idea of having a home-quality source that is potentially less prone to USB noise artifacts is very appealing.
(3) I don't have any good IEMs, and so far haven't much liked the feel in my ears of the few I have tried. I primarily use and like full-size headphones. The Oppo PM-3 is my designated "travel" (closed ear) headphone. The initial amp module available for the X7 was reportedly designed primarily for IEMs, so it's clearly not going to be optimal for my personal use preferences. But how much compromise is there? I was keen to find out.
--------------------------------------------------
Observations, notes & comments:
--------------------------------------------------
*---- about me -----*
I've been "serious" about Head-Fi gear for a couple of years. Well, more correctly have recently re-kindled a passion for headphones that started circa 1977 when I spent two weeks pay to buy a pair of brand new, state of the art Stax SR-X Mk III
*---- Sound Quality ----*
* the IEM amp module of the X7 drives the Oppo PM-3 very well. I never sensed that it was strained, or unmusical, and it probably could have made my ears bleed at full volume. Excellent match. SQ=9/10. Unquestionably way better than my FiiO X1.
* the IEM amp module of the X7 did considerably better than I expected driving a HiFi-Man 400i, on high gain. It clearly didn't have all the power and clarity of my normal desktop amp, a Project Sunrise III, and usually needed volume settings in the 95 to 110 range (of 120), but I would characterize the SQ as "Very Good," which is a 6/10 on my personal semantic anchoring scale. (10=Incredible, 9=outstanding, 8=superior, 7=excellent, etc.) I would not listen to this combo at home much, given better choices to hook-up, but in a hotel room, absolutely.
* paired with a Senn HD-650, which ought to be a poor match-up, it was, predictably, just "Fair." Somewhat muddy and strained. Listenable, but not capable of the elevating or entrancing experiences we are all looking for. Didn't get as loud as I sometimes like to listen. Doubt that I would bother to get one of the future release alternative amp modules to handle the HD-650 better. I love those headphones but they are not closed and just not well suited for travel use; for in-home use, there are better solutions, see the next two notes.
* Lineout: to the Project Sunrise III, driving any of the previously mentioned cans: Outstanding. Got a hiccup a couple of times during the week, which happened when playing 24-192 FLACs when the battery was low (which could have been coincidence), but otherwise flawless.
* Digital out to external DAC, a Schitt Bifrost Multi-Bit. Didn't think I had the connecting cables to test this, but then I realized the FiiO kit had thoughtfully included a suitable adapter for just this purpose. Super Super Super. Used purely as a transport to even better gear, the X7 works beautifully. It's at least as good as my everyday JRMC on Windows PC --> USB connection --> external DAC configuration, and probably better.
*----- UI and physical design ----*
* I mostly used the device in FiiO Pure Music mode. I primarily listen to entire albums, and thus tend to navigate by hierarchical folders. (e.g., $Music/ABC/Bob Marley & The Wailers/2002_Legend....) My tags are probably in decent shape, but I don't rely on them much. Folder navigation worked fine for me. With the hierarchy I use for folders, any album was just two or three steps away.
I am not a highly advanced Android user. It's reasonably likely that there are things the UI does that I did not discover. There's been a lot of criticisms of the UI. Maybe I have low expectations, but I found it functional enough for me, and reasonably intuitive.
* within folders, things were sometimes odd. Double-disk albums often showed Song 1, Song 1, Song 2, Song 2, etc., rather than keeping the two disks separate and in the expected sequential order. JRMC didn't do that for the same albums, so I don't think it's the tags.
* similarly, on some albums with a lot of tunes, the listed order was 1, 11, 12... 20, 21, 2, 3, 4, etc. Since I like to listen to albums from end-to-end, I prefer to hear them in the order the artists and/or producers intended. Again, could be tags, or the lack of them, but JRMC isn't showing or playing the tracks in this order. The X7 was apparently alphabetizing by track name, including an embedded track number, rather than using a "track number" tag. Maybe there's an option to control that.
* Not sure if the X7 currently has a true "random shuffle" mode. If it does, I couldn't figure it out. The default "play all the songs" order seems to be alphabetical by song. I could get that change to something that wasn't pure alphabetical, but it was too clustered by artist to be random. When I'm listening to stuff in random order, I like the idea that the Talking Heads' "Psycho Killer" could come up next ,even if an A-song like "Accidents Will Happen" by Elvis Costello was last up. It annoys me to know that as a P-song, Psycho Killer is, for sure, 1800 songs away. (How hard could it be to load a 60,000 long list of (pseudo-)random numbers into the firmware?)
* in "individual song" mode, there's an index-scale on the right-hand side of the display, from A-Z. Touching that will jump you to that part of the song list, but be patient, it takes a couple of seconds to respond.
* the pause button is just badly placed. As a right-hander, it's precisely where my fingers naturally wrap around when I hold the unit in my hand. If I had a penny for every time I inadvertently hit the pause button, I would be $34.72 richer today than I was last week. Not a deal-breaker, but it is annoying. On the X7 version ii, I hope FiiO flips the buttons, and has the ON and Pause button above the double-rockers on either side, rather than below them.
* the volume scale works well. Not sure that going to 120 is necessary ... although I somewhat enjoyed it in a Spinal Tap "11" kind of way ... but I could always find a Goldilocks volume that was "just right" for the tune, my mood and the 'phones on my head.
* Did I mention the Android UI is MUCH better than the wheel of the X1? The wheel has given me oodles of nuisance and malfunction, this is far superior. One small step for a man, a giant leap for mankind. So to speak.
*--- miscellaneous other stuff ----*
* I mostly played FLACs, the vast majority of my music is ripped or purchased as FLACs. Played up to 24-192 fine.
* DSD - I don't have a lot of music on DSD, but I do have a couple of albums and some demo files from various vendors. DSD64 sounded great, not sure I put any higher-res DSD files on the X7. Not surprisingly, the X7 would not play a 5.1 multichannel DSD file.
* MP3 - beats me. Mostly when I find any of these still hiding in my collection, I just delete them on sight as archaic relicts. Didn't listen to any MP3s with the X7.
* SACD-ISO. Tried two. One played, one didn't, don't know what the difference was.
* WAV/WV. Tried Ennio Morricone's soundtrack to The Good, the Bad and the Ugly, which is just great music for certain moods. My copy is a one-file WAV rip, it didn't play with FiiO Pure Music. I believe it did with Neutron however.
* One of the previous participants on my unit's tour apparently installed Tidal and Neutron, and (kindly or inadvertently, don't know) left Tidal logged in. Saw it in Android mode, touched the icon just to see what would happen, and was surprised when it fired up, made a Wi-fi connection with the home network automatically, and was ready to go. I did play with it for a few hours. (Okay, six hours. Until 3 am Sunday morning.) I don't think the SQ was quite up to onboard FLAC quality, but it was much better than I expected, definitely quite listenable. And so simple even this caveman could do it. Just for funnzies, I did searches for around 50 albums from my "albums I am hunting for" list, some of which could reasonably be described as "obscure." Tidal had about 90% of them. I was quite impressed with CD-quality Tidal, will probably sign-up. Streamed everything live, didn't try any "download now to play later" kinds of things.
* Neutron: played a couple of songs, just to see that it works. Not an app I currently use, and I didn't spend much time trying it out. Seems to have a lot of customization and EQ options. Noticeably lower volume than FiiO's app.
* Speaking of EQ ... don't usually use it, didn't try it at all on the X7.
* Wi-Fi - as previously stated, Tidal brought up Wi-Fi with no fiddling. Somebody else had set it up before me, so I don't know if that was much of a chore. I never experienced any kind of interference or noise using Wi-Fi, which very much surprised me.
* firmware updates - the X7 arrived as 1.0. I downloaded 1.4 as one of the first things I did after receiving the unit, followed FiiO's instructions, and it installed uneventfully. (i.e., Happy-Happy-Happy-Quick.) Never listened to the X7 with any firmware earlier than version 1.4.
* earlier today when the Wi-Fi was turned on, the X7 told me that firmware 1.5 was available and could be installed. I didn't avail myself of that invite ... something for the next person to do, if feedback on the update suggests it's essentially bug-free ... but nevertheless that's a neat capability for the X7 to have. Especially if it goes through a period of regular firmware updates as more capabilities and fixes are added.
* Loaded up a bunch of xmas and "regular people" tunes on a new micro-SD card in preparation for the annual xmas "obligatory 2 day holiday tour around the state to visit various relatives." Was thwarted in my effort to share good music cheer because the X7 and my vehicle (2013 Honda Odyssey) were not able to to find each other to make a BlueTooth connection. Was on the road and didn't get to fiddle with it much. (Unfortunately, I had assumed the BlueTooth would work, and neglected to also bring a line-out cable as a backup. Whoops. Had to listen to the radio, how retro 20th century. Under my reindeer antlers headpiece, I was secretly embarrassed by this technology failure. Fortunately, the wifelette was pre-occupied with hitting the travel schedule.)
* Battery life: I didn't really time it, but from my experience 8-10 hours seems a good guess. And remember, I'm using cans that need more power than IEMs would. That's enough for me, anytime I know I'm going to be unable to recharge for more than 8 hours, I have a number of cheap "recharge your mobile device via USB" batteries I can bring along. (They're a commodity accessory now, $10-$15 for 3000 to 6000 mAh.)
* Recharge via USB --> fast. I'd guess it took less than 2 hrs to go from 6% to 100%, while the X7 was playing.
* USB connection to PC. Worked fine for a while. Plug in the USB cable, and up popped a "Connect in Android mode" screen. But that is not happening now, in either Pure Music or Android mode. Don't know if I inadvertently turned something off on the X7 or on my PC. Regardless, loading tunes onto a card is usually faster for me if I plug the card directly into a card-reader on the PC rather than use a USB cable to an external device anyway, so I generally do not move tunes via a USB cable.
* re-scanning the list of tunes: the X7 took 80 seconds to scan the internal storage and a 128-GB card, and to register 2,930 tracks. I was happy with that. (The track count for that size card is kinda low, because I put a large number of high-rez files on the card for testing purposes, and of course those files tend to be much larger than normal 16/44.1 redbook files.)
* I LOVE that FiiO isn't burdening the X7 with a ton of expensive internal storage. With a card slot, we get essentially unlimited storage capacity, as much as anyone wants to buy, and can purchase whatever size cards offer the best capacity vs price trade-off, any given time. To me, at the moment the 128-GB cards are still the sweet spot. Because the X7 rescans a memory card so fast, swapping a new card in is no big deal. (Unless you drop the old one on the floor of a crowded public transit bus in the dark, etc. Some free advice: don't do that.) Two card slots would be nice, but it's not essential.
*----- bottom line ---*
I like the FiiO X7 a LOT. Even with the IEM amp module, SQ was excellent on full-size headphones that are reasonably well-matched. Super as a transport to desktop gear. No show-stoppers in terms of usability from my point of view. Its functionality with Tidal is making me re-think about the fun and usefulness of wireless streaming, which up to now frankly I had not seen much point to.
Will it rip the guts out of the market for top-end A&K models? Don't know, but it will certainly push them as "a value proposition." Hate that phrase, but it fits here.
How does the X7 compare to other hot new DAPS, such as the Questyle Q1PR, the Onkyo DP-X1, or even the LG-V10 ? Don't know that either, haven't had a chance to play with any of them.
But I would say that if SQ is your #1 consideration, which IMO it certainly should be, then the X7 is most certainly a very serious contender, as is.
i had them over 20 years: they took longer and longer to get up to volume (like a tube radio) when i first turned the power on...
you're lucky yours still work!