My PC has very limited mixer options for recording

Cause - Outdated Audio driver is installed

The original Realtek Audio driver did not allow for separate volume controls to be enabled when recording; there was one master slider that controlled all volume levels. This was known as 'mix-mode' support. The driver has since been updated to allow for more control in recording, with separate sliders now supported (see the image for details). Visit Cybernet to download the latest audio driver.