Mobile Setup: Active DI Box W/summing Amps

[supersession2001@aol.com]

Recently I read an article from a magazine that was regarding recording keyboards and their functions as a controller and use of making beats. The Engineer in the article states that his signal flow to multitrack is "the keyboard modules running into an active DI box that has summing amps in it and then out of that right into Pro Tools". What is the purpose of use of summing amps? Why cant you go from modules into Pro Tools? Thanks, Rob

[reignstorm]

A summing amplifier adds 2 signals together. In a keyboard application I'm not sure why this would be needed. Perhaps he feels its better to take the left and right signals of a stereo mix and sum them into a mono signal rather than just take the mono off the keyboard. I really have no idea but thats all the summing amp does. It gives you 1 track output from 2 track input.