As a reply to these posts:
http://www.head-fi.org/t/735828/gustard-h10-high-current-discrete-class-a-output-stage-headphone-amplifier/3075#post_11860820
http://www.head-fi.org/t/735828/gustard-h10-high-current-discrete-class-a-output-stage-headphone-amplifier/3075#post_11860854
I am posting here to avoid off topics.
@Noodlz
@stuartmc
Today I had the chance to finally compare directly two DACs I own: the Yulong D200 and the Gustard X12.
All the listenings were made through my linux player (ubuntu server 15.04 + mpd + upmpdcli - Atom D510 with a Linear Power Supply).
Also, the Schiit Wyrd was always used. The headphone amp is the Gustard H10 while I have used my best headphone, the Sennheiser HD650.
Test setups:
1) Player -> Audioquest Cinnamon 0.75m -> Wyrd -> Audioquest Cinnamon 0.75m -> Yulong D200 -> Balanced Cables -> Gustard H10 -> HD650
2) Player -> Audioquest Cinnamon 0.75m -> Wyrd -> Audioquest Cinnamon 0.75m -> Gustard X12 -> Balanced Cables -> Gustard H10 -> HD650
2) Player -> Audioquest Cinnamon 0.75m -> Wyrd -> Audioquest Cinnamon 0.75m -> Gustard U12 -> Ricable HDMI Cable -> Gustard X12 -> Balanced Cables -> Gustard H10 -> HD650
There are no night & day differences, but I would say setup 1 is the one which delivers the least amount of details. Also, the listening was definitely more fun with the X12. I think this is due to a more dynamic presentation.
The X12 behaves even better when using the U12 and the I2S (via HDMI) connection, which is my current setup.
Of course, I could not use the Yulong U12 interface with the D200 (at least not with a I2S connection, and I did not have the time to try coaxial, but this would have multiplicated the setups).
In this test I did not use the D200 built-in headphone amplifier. The D200 is quite good as a stand alone dac/amp, but it just cannot compete with the Gustard H10 as a Headphone Amp.