Hey Silly
The post before this one is very relevant to your question so also have a look at that.
Basically you should try to keep the gain on the Roland as low as possible. Up the gain on the Behringer until it clips and then back it off a bit. Unfortunately it doesn't give you a PLF level so you have to use this method. Up the volume level on the "B" until you get an adequate level on the recorder. It should be pretty much that simple. If your levels are a bit up and down during the performance you might want to use a bit of compression. Not too much though (also see previous thread).
Good luck, I'm looking forward to hearing some results.
Mark

Hello,

So, I guess I'm assuming that the level knob is actually basically acting as a fader would and I would set it at zero while setting the gain correctly? Then if needed add or take away a bit?

Silly

Got it in one :D
Obviously it's hard to put a fader on something so small.
BTW Make sure you're running a balanced TRS lead between the mixer and the Roland. It will cut down on noise.

Sillyman,

Just think of the "gain" knob on any unit (or channel strip) as a volume knob for the input jack of that unit (or channel strip). The level knob (or fader) controls the output of the unit.

curvedominant