One truth about working with audio is you always need the cable or adapter you don't have in your toolbox. That's why we love these terminal-block audio connectors so much. No soldering required! Use stranded or solid core wire and a small screw driver to create custom wiring jigs.
This is the 3.5mm (1/8") Stereo Audio Jack Terminal Block. It's the most common size and style of audio connector, used in most headphones or basic audio connections you're looking to make.
We also have a (matching) Stereo Audio Plug Terminal Block