Chris, I used this for a bit before sending it back. I got some good results, but found it 1) easy to brickwall and 2) was limited because of the three gain settings. If you would like some samples, I'm sure I can dig something up. I was going sp-cmc-4 > sp-preamp > jb3.
The batt box with preamp is different. As that can also have bass rolloff. That was also something I didn't like about this preamp. You couldn't do any rolloff with it.
Honestly, I would look at an sbm-1 or denecke ad-20 instead of the SP preamp.
J