I can record through the USB connection, but not any playbacks
The setting of the Speaker icon in the device toolbar should say your USB device.
http://manual.audacityteam.org/man/device_toolbar.html
My little stereo USB thing says “USB Audio CODEC.” You should know Audacity checks for new devices when it starts. So plug everything up, let it settle for a bit and then start Audacity. You can also use Transport > Rescan.
Koz
Thanks, It is working, Rescan!