Thanks very much for the replies.
That clears things up for me a great deal.
I am most likely going to go ahead with the second hand set of V800 + V200 to power my headphones. but before that, some final questions:
1) Seller claims the V800 has never been opened or modified and its less than 5 months old
the V200 has been opened to change power input from 110v to 230v (just a jumper wire)
this is what the seller claims. Is this a good buy in your opinion?
2) I would like to know if it is possible to connect the V800 to both the V200 and my KRK's? (i.e connect to V200 using Balanced and using RCA unbalance to connect to the KRKs). If yes, will the KRK's automatically go on mute when I connect my headphones?
appreciated