[Bill Denton]

Sorry, guatamas...but do you really think somebody who does not yet know how to connect a preamp needs to get involved with patchbays and such? I know you meant well, but it's best to match the advice to the audience...

Now...to the OP...here's how you do it...

Obtain two cables with 1/4" TRS (tip/ring/sleeve) connectors on both ends. These are called balanced cables, and the connectors shoule look like the 1/4" connector on a pair of stereo headphones. The cables should each be long enough to reach from the Pro MPA-II to the Mbox Pro.

On the rear of the Pro MPA-II, plug one end of each cable into each of the 1/4" balanced outputs (one cable plugged into Channel 1, the other cable plugged into Channel 2).

Locate the cable that is connected to Channel 1 on the Pro MPA-II and plug the other end into Line Input 3 on your Mbox Pro.

Locate the cable that is connected to Channel 2 on the Pro MPA-II and plug the other end into Line Input 4 on your Mbox Pro.

(By convention, odd numbered inputs/outputs are used for the left stereo channel, even numbered inputs/outputs are used for the right stereo channel.)

Ensure that the +4/-10 switch adjacent to Line Inputs 3 & 4 on your Mbox Pro is in the out position, for +4 dBu.

You will not be adjusting any "input levels" on the Mbox Pro, you will make all adjustments on the Pro MPA-II.

The manual for the Pro MPA-II contains very good instructions for its operation...I recommend you read and follow them.

When recording in Pro Tools (or any other DAW), you will want to adjust the Output Level and/or the Master Output Level control(s) on the Pro MPA-II so the level meter on the audio track you are recording reads an average of around -18 DBFS.

Good luck...