Audio Direct Box prototype.

EasyEda is really an interesting PCB creation tool. I often use it for fairly simple circuits, and it does its job very well. I am currently working on the prototype of one board of my futur multi direct box :

Selection of one of the three unbalanced sources and electrical isolation and symmetrization of the output signal. 

Obviously, it's a little more complicated than performing this function with an audio transformer. And then I would probably have some modifications to make to the schematic based on the measurement results of this prototype...