What makes 6v better than 2v

[Ermos (Erno)]

I think I have answered your question already last November:

Which cables for Bartók + Diablo 300?

Hi, and welcome to the community. The Bartók does not have balanced inputs, but balanced outputs. The input sensitivity of the Diablo 300 is 0,617V, so it is best to output your Bartók at 2V, if you connect it directly to the Diablo without a preamp. Which you do, of course, because the Diablo 300 is an integrated amp.