I'm venturing into the world of rack components, but I want to start off slow. I'm going to get a power amp and use the preamp of my SWR350 (if possible) until I get a rack preamp. My question is: Can I run the preamp on the SWR safely without hooking up speakers to the SWR. I've looked hard at the manual and they really don't address using it this way at all. Any and all suggestions are appreciated. Thanks!