Setting up Pro-Ject Tubebox SE II


I have a Lyra Dorian MC cartridge paired with my Pro-Ject Tube Box SE II. According to the cartridge's specs:

Recommended load direct into non-inverting RIAA equalizer amplifier or head-amplifier: 100ohms - 47kohms (determine best impedance value by listening)

According to the tubebox instructions:

"MC - 100ohms/120pF (jumper on 100 Ohms)"

My question stems from the fact that there are two sides to place jumpers* on the back of the tubebox yet the tubebox instructions speaks in the singular, it does not say "jumpers" -- thus am I supposed to only place a jumper on 100 Ohms on one side? I'm confused as to what the "load" actually does anyway.

Help would be very much appreciated.

Thanks!

*Picture of the back of the tubebox:
http://tinypic.com/r/nxkm10/3
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