This is a known problem with the latest Windows 10 update. You will need to log directly into the CasaTunes server to correct this issue. If you don’t have remote access, you’ll need to connect a monitor, keyboard, and mouse to the server before proceeding with the following steps:
1. Open Windows Playback Devices.
2. Select “Speakers (Realtek High Definition Audio)” and click on “Configure”.
3. This will most likely be set to “Stereo”. Change the selection to “7.1” and proceed through the prompts until you click “Finish”.
4. On the CT-8+, you will need to repeat step 3 for the “Speakers (ASUS Xonar DSX)”audio card.
5. You might need to reboot the server or restart the CasaTunes service, but this step is sometimes unnecessary.