Thanks Moke!
Here is my take on it. Get as much gain as you can from your preamp, leaving some headroom. Then simply start at off with your recording device at zero and bring it up to where you get good levels. This only works if your recorder has a line input. If your using a mic input, you could run into trouble. The only reason why someone would say run the recording device wide open, is that the preamp overloads easley, and in order to avoid distortion it forces you to turn the gain down on the preamp. Not a good way to get a low noise floor. I know of very few recorders where, if you did run it wide open you would not get the Niagara falls of noise floors.
The reason you bought a preamp is to reduce noise, Like a good power tool let the external preamp do the work. That being said you have to be careful not to use to much gain, or you will overload your line input on your recorder.
Most people are not aware that just because your volume is down on your recording device, does not mean that you can not still overload it. Level indicators on digital recording devices are not an actual indication of clipping, because they are measuring level in the digital domain. The analog section of your recorder can still be overloaded with out you knowing about it. So get to know you gear, spend some time in a very quiet room and get your levels set so you have very little hiss and good levels. This may mean running the preamp out full, and the recorder almost off or the opposite.
Its kind of confusing I know but remember that your recorder uses digital attenuation, it does not have a analog input gain control like your preamp does. So when you reduce level on your digital recorder the first stage of amplification is analog. It is not being controlled by your recorders input or recording level. It is simply run wide open most line input can handle +4 db before distortion but not all. So a good rule of thumb is to run around -10 into a recording device ( as measured from the actual output of your preamp) then adjust levels in the recording device from there. These are only guidelines, and NOTHING is written in stone. In the end you still have to sit in your quiet room, and play with the levels until your happy. Good luck and remember, Chris at SP is a very nice guy and he would also be very happy to answer your questions about your new preamp.