These CS3498 DACs looks quite nice, but I have no idea about the engineering behind them...
What other DACs do you have? The difference between a cheapo DAC and a more expensive DAC does have significant differences. Also, you say you don't hear a difference between amping the HD800s and listening to them straight through the headphone jack of your laptop ?
I'll be bringing quite a few HE cables and maybe we can do some blind tests on the cables. Would be very interesting indeed, I am a cable believer, but let's see if the people who believe in cables can actually make out a difference.