My Sansamp RBI acting as the pre and my Mesa 400+ as the power section. For clean volume my setting used to be at 7 on the master and it was still growling a little. Here with the RBI put into the effects return, I get deep full active midrange goodness with stupid headroom. My master is now set at 2-3 for the same playing situation. Now don't hate. My Pbass thru channel two (D-180 pre)cranked is still powerful but this TOTALLY solved any clean headroom issues I was having with active basses with unexpected awesome results. Still grunts like a tube amp too.