The CTR2-Mini Audio Controller, along with Audio I/O modules for each radio adds the ability to share two microphones, your headset, and you PC’s sound card with all of the radios in your shack.
The audio controller is available as a printed circuit board (PCB) kit or as a completely assembled unit. If you are comfortable with your soldering skills, the audio controller can be built in just a couple of hours. I don’t recommend it to be your first adventure in kit building though.
The manual below will describe the audio controller’s operation and step you through building it. You can read it here or click the download button to get your own copy to print out. The manual has the circuit description, schematics, and bill-of-material lists where you can order the parts to complete the PCB kit.