All Play Controls - This option displays all your soundcard play controls. The controls in the displayed image are Stereo Mix, Mono Mix, Aux, Video, CD Audio, Line In, Microphone, Phone and SPDIF.Not all controls will have application in PSK31 Deluxe but you will probably need to know how to use those that are associated with input and output levels. It is also handy to know how to mute the PSK input (received) signal so that it doesn't drive you mad. It's not necessary to hear it. You can see it.