I have understood you can use SansAmp as a preamp, and by going directly to poweramp you could get huge tone, great portability and perhaps even save few bucks. Opinions? So, are there what cheap poweramps out there, and what about prices? I know Mackie has a range of inexpensive watts out there for one. Also, can you use any poweramp with bass-preamp(or SansAmp in this case)?