I have the Xonar D2X, the "Tick-tock"-sound is the amplifier turning on, if you want to get rid of that sound you have to get rid of the card
As for the other sound, it might be an unlucky coil whine (my old 7800GTX made that unbearing whine noise that changed pitch under load). Does it come from the speakers or from the computer itself?
And I STRONGLY reccommend 3rd party drivers
, Asus' software support is absolute crap. The only thing I use from their site is the hotfix for a "left-right audio swapping at random" issue