I have used two of those Radio Shack adapters. They are big, long, and heavy and don't last very long. The only way I would use one is to lay it on the floor and run a balanced cable from the mike to it and then run a 1/4 inch cable from it to the keyboard. It is not too bad if you plug it directly into the mike but I would not plug it directly into the keyboard. It sticks out too far, and is too heavy for the normal 1/4 inch phone jack. It is an accident waiting to happen.

Tom