Just got an Xtant 301a this past weekend and been trying to get familiar with all the settings and jumpers. I read the tutorial on how to set the gain and it looks pretty straightforward with a AC volt meter. My problem is the input gain. What is it? http://www.xtant.com/html/techSupport/pdfs/301aIns.pdf I dont know if it's related to the input gain or not but when I first got the amp on Saturday, I took out my friends amp and put mine in. Played some music and the woofer didnt play very loud at all.