Folks,
I just added a used SF-2 to my rig, and all I can say is if you don't have one, and can afford one, get one. That one piece of equipment makes every bass I own sing, and I'm not exaggerating. I plugged in my '76 Rickenbacker 4001 this evening, and you would have thought Chris Squire had just picked up my bass and started playing (not my playing, mind you - the sound!). My God, can that piece of equipment make a difference.
I'm using an Ampeg SVT-IV Pro, and basically I use the SF-2 as my tone control (the EQ on the SVT-IV is set flat, with all the treble and bass boost buttons on, mid shift all the way to the left), and I am just amazed at the sounds I can conjure from it. I hook it up by running th biamp outputs to the inputs of the SF-2, and then the outs from the SF-2 to the inputs on the SVT IV. It works great.
I know there have been a lot of posts singing the SF-2's praises, but I just had to say something. Like I said, if you can lay your hands on one, do so by all means. You will not be disappointed.
Alan