Hi, getting things how I like it but wanted to check about DVC. I use bluetooth from my tablet to a hifi, settings flat, then listen more with headphones again now set at flat, just upgraded cable for them. The dvc button is set on on by default, the only difference I have noticed is that if I turn it off, it gets quiter, ie volume needs to go up, is it right to leave it turned on or am I missing something.