Setting analog input and output level

Make sure Toolbars->Levels (and Mixer) is checked or click the  button. Now the mixer you have selected in the sound card settings, if any, will be displayed. Shown below is the WinMLS mixer.

Set the volume sliders to a low level as shown above and connect the device you want to test. Note that you can use the keyboard arrow keys to do small volume changes, but you must first click at the volume slider to set it active.

Note: If WinMLS is not set to control the Windows mixer in the sound card settings, the dialog it will look like below, only displaying the input levels and not the volume sliders.

In this case, it is not possible to set the analog input or output levels from WinMLS.