the ampeg svt II-p, please help

I just picked up this preamp but I have no idea what it's all about. If anybody has any information on this please let me know (unfortunatley mine came with no owner's manual). Currently I'm running it through a crate spa-200 power amp and an ampeg svt 18-e, also of which i don't know enough about. I'm tryin to get a good sound out of my EB and my DB that can sustain a loud band. please help a brother out
thanx alot and peace be unto you