My preamp is a Ampeg svp-bsp. I run my clean channel at about 12 on that gain and 3 on the volume and about 3 on the Master. Any time we have a guy running sound all the do is bitch about the hissing. It has a d.i. on the back as well. Any recommendations on how to get sounds guys To quit bitching about a little hiss When they cant ever seem to get my sound right?