Bravia oled KE48A9 Picture quality

[Gaggy75]

Purchased this tv a couple of days ago and am struggling to be convinced about the picture.

I know that between SD and HD channel's there is a massive mount of upscale the TV has to do, but I am finding HD channels or programs the images appear to be grainy and not as sharp or clean as I thought. 

 These are the leads my Virgin 360 box and tv are connected by so they are correct.

Has anyone else found or knows a way of changing the settings so it will improve?

Thanks