When installing the Startech SVID2USB23 which is a (composite or compound) USB device it "may" only expose (one 2861 device under "Sound, video and game controllers" within Device Manager ) [STOP] everything.. this is indicative of a Bigger Operating System problem under Windows 7.
The C:\Windows\inf\usb.inf file is ('missing') and it will not be detected as missing even with sfc scannow.
"The usb.inf file is also not one of the 3498 files that Windows File
Protection looks after, so there is no backup copy on your system."
Many back up copies exist on your system, a file search for "usb.inf" with a tool like voidtools "Everything" will find them for you, and possibly Windows search targeting the C:\Windows subdirectory (although I gave up on Windows Search long ago and disabled it).
Simply copy one of the usb.inf "backups" into the C:\Windows\inf directory and unplug and re-plug in the 2861 device (SVID2USB23).
The first device that appears in the "Sound video and game controllers" represents the first Endpoint in the cable dongle, the video capture device.. the sound device is the second endpoint on the bus and fails to appear without usb.inf.
Once the usb.inf is in place the first endpoint will be detected as [ Imaging Device 2861 ] and the second endpoint as [ USB Audio ] and appears as [ Line (2861) ] in the Windows Sound Audio Mixer "Recording Devices".. a correct "Update Driver" and installing the EMAudio driver will convert that into Sound device (2861 Audio)
VLC is one of a few programs which can properly enumerate USB Audio device as selectable Audio Input for recording or playback. Many legacy audio capture programs will simply list "Master Volume" and not give you a choice from all available audio sources. Without this level of control.. the Audio Input from the USB audio cannot be turned on or have its levels set.
The SVID2USB23 aslso has S-Video and Yellow Composite Video inputs.. if you recieve a black blank screen on recording it may need its crossbar video input switched over to the S-Video Input to cpature video signal.
More usb.inf info here:
USB Generic parent driver
And more specifically here