Step 6: Improvements and more.
With more switches and audio jacks its possible to expand this for more inputs/outputs where each additional switch adds room for one more connector.
A larger switch with 3 poles instead of two and some spare audio cord may help to reduce any signal degradation.
Connecting the center leads of two switches will allow selection of multiple inputs as well as outputs.
If your wire is more flexible or your confident with your skills you can connect a single wire from each connector directly to the switch eliminating that center soldering point.
All comments and suggestions welcome.