They do look strikingly similar. I doubt they are the same headphone rebranded, but who knows. Maybe Fischer really liked the design and decided to use it as the "base" for their own design. I woudn't trust turtle beach for quality is all I mean, and Fischer is a Russian Company I believe.
To DoritosMan, I am a console gamer, so I don't know a lot about computer sound cards, but this would be my guess. If your soundcard has Dolby Heaphone, or some other Surround sound emulator built into it, than a dedicated amp like the FiiO would be better. It is obviously a superior amp. However, if your card doesn't have that feature, but it can output optical audio, than a Mixamp, which can decode the signal would be your choice. Being a console gamer and avid movie watcher I use the JVC/Victor SU-DH1, which is similar to the Mixamp, but with DTS also. The amp section is not as good, so I run it to a dedicated amp. It is a more expensive option.
OK I just reread your post and looked at your motherboard. I would just stick with the onboard audio, run optical out to a mixamp. I have read it has more than enough power to run the AD700s, and should make for a rather simple solution.
Edited by TruBrew - 3/29/11 at 8:42pm