This amp has two inputs, a 0dB and -15dB. What is it useful for? In my band, I use -15dB when I'm playing more in the pocket and 0dB when i'm playing out more--is that wrong? Also, how do you work the effects? I had a really nice fuzz effect, but it is gone now and I can't get it back on my footswitch. I do have a chorus programmed onto one of the knobs however. Thanks!