I'm not a home right now, but just going off the figure in the manual:
http://www.taperssection.com/reference/pdf/Manual_EAAPSP2.pdfThe switches from left to right:
Battery: Up (turns unit on)
Mic/Line switches (L/R): If you're connecting your mics to the XLR inputs, then "Mic"; if you're connecting a 1/8 into the line-in, then "Line"
Phantom: "24/48" for standard mics connected to the XLR inputs
Mic Sensitivity: I found these numbers to correlate roughly to the amount of gain, so for "-35" it is about 35 dB gain. Likewise for -55 and -70. I usually leave it at "-35" (that's the minimum amount of gain).
Bass roll off (L/R): I usually leave it off, and adjust the bass in post if necessary
Gain: I usually leave this at 0 dB.
If you set the Mic sensitivity higher than -35 or the Gain at +6 or +12, you can see if you are clipping by the "Peak" lights which will start to glow when clipping.
Hope that helps! I'll try to edit this post with a photo later on....