Another question that I cannot find the answer to comes from wanting to run a keyboard or guitars through the board. Since I plan on using all 4 mic/line ins for mics, I am forced to move for the stereo inputs for the rest. If I want to plug in a keyboard, acoustic guitar, or headphone out of a small guitar amp into the board should I use a DI box? If I use a balanced cable without a DI box will a ground loop still occur, since it has a ground wire? Also, should I use just one mono 1/4" into the left stereo port, or convert to 2 separate 3 pole (TRS?) plugs and plug into both stereo channels for guitar and keyboard?