You can access all the channels on your soundcard's mixer with wmmixer. Most
common channels are identified with an appropriate icon.
Controls include a stereo (mono where appropriate) volume control and a
recording source toggle button.

Press the "<" and ">" arrow buttons to select a channel.
The icon identifies the current channel (a volume symbol with a question mark
represents an unrecognised channel).
Click and/or drag the volume display to set channel volume.
There is a also a button to set recording sources.

Homepage:
https://www.dockapps.net/wmmixer
