Okay, here is the deal. I have an AMPEG B2R head(4ohms) and the svt410hlf cab (4ohms). I want to use this presonus preamp/compressor(2ohms)(http://www.presonus.com/pdf/EurekaMAN01.pdf) with my set up. With the presonus equipment at 2 ohms, can I run from my bass(Musicman Stingray) to the B2R then B2R into the Presonus pream/compressor and then to the cab? I know that since the Cab and B2R are both at 4 ohms I can run with no problem but I'm not sure how the preamp should go into the set up. Thanks in advance for your help.