This is my first review, so please be gentle with me.
I don't know much about the mumbo jumbo of audiophile terms. And as usual, disclaimer: This what I hear and feel on my rig. Don't flame me for it. And no, I'm not a shill as I live in New Zealand.
I'm comparing TC-7510 (around 100 hours burn-in) with Xindak DAC3 mk2 (with tube buffer).
Equipemnt:
Headphone: AKG K340
Source: Foobar2000 -> Flac -> USB -> MM Gear USC-100 -> Optical out
DAC: TC-7510 (GBP 90) vs Xindak DAC3 mk2 (around US$400)
Amp: TMS T-200
IC: Cheapo/standard IC. (see my previous post, the TC-7510 can't handle my vDH C5)
Guitar: (Sonata in C minor K466)
Winner: Xindak.
Xindak is more expansive, details are easily heard and more enjoyable. The decay of the string is there.
Xindak is more airy too, i think this is got to do with it having a tube buffer. TC-7510 have more "black" background though.
Piano: Ludovico Einaudi (Stella del maattino)
Winner: Xindak
Again, Xindak is more expansive. I have to say that it "seems" like TC-7510 extend higher than Xindak.
Bass: Aqua - Lollipop (remix)
Winner: Xindak
Xindak has fuller bass.
Vocal: Andrea Bocelli (L'Attesa)
Winner: Xindak
Andrea voice is weightier and crispier (such word exist??)
Vocal: Sarah Brightman (A whiter shade of pale)
Winner: None with TC-7510 slightly preferable.
I guess this because TC-7510 has a darker/blacker background that makes her voice come out more clearly.
General: Maroon5 (Sunday Morning)
Winner: Xindak significantly
This is my "reference" song as it full of subtle sounds from everywhere.
TC-7510 feels less congested, but boy all the details is missing. all that small nuances that makes this song very enjoyable (for me) is gone. I can only hear "major" things with that small things fade or only almost audible. Xindak is grainier than TC-7510 though.
Conclusions:
In general Xindak are louder than TC-7510. Mind you, some people believe that this Xindak is comparable with $2000 DAC. I never heard a $2000 DAC so, can't comment on that. What i try to say is that Xindak is not a bad DAC and it might not fair to compare them.
I want to like the TC-7510 as I purposefully want to downgrade (this is my office rig and I work with monkey. Having a tube headphone amp is constant nightmare). Although Xindak is the clear winner, I don't mind getting rid of it and the TMS T200 headphone amp and just happily live with the TC-7510. I might have to find a more efficient can as this AKG K340 is really picky.
The headphone amp part of TC-7510 although lack the juice for my K340 but never-the-less is pretty good. Word of warning, when i plug my UM2, it has a loud hiss and humm. I guess other people already mentioned this. but if you use higher impedance can, it seems to be just fine. I try my colleage Senn H555 (50 ohm) and is fine with no audible hiss or humm and is more than enough to drive it.
So, for those newbee like me, on budget and have a pretty efficient headphone, TC-7510 is still a very valid option. Surely it can't compete with a more dedicated/expensive unit but it can holds its ground with those that twice it price, especially when you consider you get the headphone amp.
Hope this help.