your hdva600 will not colour the sound,it's been made 2 drive the hd800s probably . using this amp with the balance cable will give you the best results you're ever gonna get with the hd 800s.So really it's all down 2 the dac your using,the better the dac the better your hd 800s will sound.l use the hdvd800 which is the same amp as you, but with a built in dac, which I don't use.i use the chord hugo as the dac and could listen 2 it all day and all night like this . Just find the right dac for you.the hd800s are one of the best headphones you can get at the moment,they tell it as it is.
Not exactly true. As discussed at length in this thread a couple weeks back, the Senn amps have an output impedance of 40 ohms, which does boost the hd800s bass. Purrin posted some very cool graphs documenting this effect a while ago using several different impedance adapters to show the impact on FR. With push pull and dual mono amps, running balanced doubles that output impedance and the resulting bass boost. I'm not suggesting that there is any objective good or bad in this, but it is definitely coloring the sound.