DIY Passive Summing Mixer...

So this fellow on Gearslutz by the name of Mitchell decided to make himself a passive summing mixer. This flavor of summing has no make up gain; you use mic pres to bring the level back to line; in this manner you can determine the color of the summing. (The Rolls Folcrum follows this line of reasoning.)

Anyways, there are many more pictures in the pertinent thread. This is actually, as you’ll see from the interior shots, a fairly simple project. A lot of wiring, to be sure, but nothing terribly complicated.