So most importantly, how does it sound?
Went through my whole demo list first with Sansa + GR07. This is the first time I've actually done real, critical listening with this player, since I only ever use it while commuting, where SQ isn't a huge priority. It's not bad, but listening to it now in the context of my other headphone evaluations (my full-size headphone rig(s)), it's definitely lacking. Imaging and soundstage are so-so. Bass is lacking. And highs in particular are either missing or somewhat shrill. It gets "congested" when the music is loud and thick, meaning it gets hard to distinguish individual instruments, especially with a big orchestra. And it seems to have little headroom; even with IEMs I generally need the volume almost all the way up, maybe 80-90%. It lacks... oomph. (Yeah yeah, deeply scientific, I know.)
Granted, this is not a fair comparison; I think I paid all of $60 for the Sansa from Dane several years ago, so I was never expecting it to be stellar. Its prime selling point is its small size.
By contrast, with the DX90 + GR07, I get a sound that's much closer to what I expect from a quality system. Imaging and soundstage presentation are much clearer. Highs are more precise. The bass on the GR07 isn't extreme, but it's maybe a little fuller with the DX90. But that sense of congestion is gone. Even with music loud and full, imaging and depth/layering is still very good. It just feels like it handles even dense music much more easily. And with the DX90, I don't think I ever had the volume up more than about 60%, even on the lowest gain setting which I found I preferred (it has three - low, med, hi). Just... more headroom, it seems.
So it's definitely a big step up.
But take this with a grain of salt. First, I'm only comparing these two players here, and the points above are relative. Second, I'm not an IEM guy, I don't have a lot of experience with them. While I think the GR07s are pretty nice, they're far from top-of-the-line IEMs, and I still vastly prefer my full-size headphone rig. And the tube amp; as good as the DX90 sounds, without trying to reopen the tube-vs-ss discussion we've already had, it has that "solid state" feel to it that is not my personal preference. I'll leave it at that.
Anyway, I'm quite pleased with the upgrade, both in the SQ and the interface and storage capacity. Maybe someday I'll get some better IEMs. Maybe... that's just not my thing. And maybe I'll try the DX90 with my full-size headphones just for kicks. I suppose I could even compare the DX90 as a USB DAC to my Yulong DA8... might be interesting. But that's for the future. For now, I'll spend some more time with the DX90+GR07 combo, and get to know it a little better.
And speaking to my pet peeve I mentioned earlier, the DX90 will in fact play sequential tracks without interruption, yay!
Oh, and the last plug I'll put in for the DX90 is that it has a removable battery. So if you were using it on a long trip, you could take along spares. I'm pretty sure the Fiio X5 doesn't do that. Can't comment yet on the battery life, but it's supposed to be ~12 hours or something... we'll see.
Went through my whole demo list first with Sansa + GR07. This is the first time I've actually done real, critical listening with this player, since I only ever use it while commuting, where SQ isn't a huge priority. It's not bad, but listening to it now in the context of my other headphone evaluations (my full-size headphone rig(s)), it's definitely lacking. Imaging and soundstage are so-so. Bass is lacking. And highs in particular are either missing or somewhat shrill. It gets "congested" when the music is loud and thick, meaning it gets hard to distinguish individual instruments, especially with a big orchestra. And it seems to have little headroom; even with IEMs I generally need the volume almost all the way up, maybe 80-90%. It lacks... oomph. (Yeah yeah, deeply scientific, I know.)
Granted, this is not a fair comparison; I think I paid all of $60 for the Sansa from Dane several years ago, so I was never expecting it to be stellar. Its prime selling point is its small size.
By contrast, with the DX90 + GR07, I get a sound that's much closer to what I expect from a quality system. Imaging and soundstage presentation are much clearer. Highs are more precise. The bass on the GR07 isn't extreme, but it's maybe a little fuller with the DX90. But that sense of congestion is gone. Even with music loud and full, imaging and depth/layering is still very good. It just feels like it handles even dense music much more easily. And with the DX90, I don't think I ever had the volume up more than about 60%, even on the lowest gain setting which I found I preferred (it has three - low, med, hi). Just... more headroom, it seems.
So it's definitely a big step up.
But take this with a grain of salt. First, I'm only comparing these two players here, and the points above are relative. Second, I'm not an IEM guy, I don't have a lot of experience with them. While I think the GR07s are pretty nice, they're far from top-of-the-line IEMs, and I still vastly prefer my full-size headphone rig. And the tube amp; as good as the DX90 sounds, without trying to reopen the tube-vs-ss discussion we've already had, it has that "solid state" feel to it that is not my personal preference. I'll leave it at that.
Anyway, I'm quite pleased with the upgrade, both in the SQ and the interface and storage capacity. Maybe someday I'll get some better IEMs. Maybe... that's just not my thing. And maybe I'll try the DX90 with my full-size headphones just for kicks. I suppose I could even compare the DX90 as a USB DAC to my Yulong DA8... might be interesting. But that's for the future. For now, I'll spend some more time with the DX90+GR07 combo, and get to know it a little better.
And speaking to my pet peeve I mentioned earlier, the DX90 will in fact play sequential tracks without interruption, yay!
Oh, and the last plug I'll put in for the DX90 is that it has a removable battery. So if you were using it on a long trip, you could take along spares. I'm pretty sure the Fiio X5 doesn't do that. Can't comment yet on the battery life, but it's supposed to be ~12 hours or something... we'll see.
I'll never get as "high end" in the upper stratosphere of performance with a speaker system as I have some access to with headphones.