I'm in the process of borrowing a friends AV head since he is now switching to guitar and is trying to sell his bass gear. I've been playin it alot and i'm really liking the sound, but i noticed something on the back with the bias control. I have 1 green led lit up on my bias 1 control but on my bias 2 control i have a green and a red, what does this mean? It says look in the manual but he nor i have it anymore, i was gonna take it to my friend at the music store but figured i'd check what it could mean if i'm getting a red led lit up. This is the first time i've ever had a all tube head so im not all sure what the problem could be.. i don't hear anything wrong with the amp and he told me he re-tubed it a few months ago. Any ideas?