I was messing about yesterday evening and with then gain at 12 o'clock I can get a nice grindy tone, but the master is only at 7:30 (7 o'clock being volume off) so the power stage is barely ticking over. With the gain at 8-9 there's, not surprisingly, a big change in sound when you turn the master from 7:30 - 8 o'clock.
So whilst I can get a grind tone at home volumes, it not as full sounding as it can be...,