When multiple AIRA Compact units (including the T-8) connected via USB to the same computer are mutually connected via the MIX IN/OUT jacks, a humming noise may occur due to a ground loop. This is a common phenomenon that can occur when connecting multiple audio devices to the same computer in this way.
To confirm the cause:
- Disconnect the MIX IN/OUT jacks and check whether the noise disappears.
- If the noise is caused by a ground loop, try the following:
- Connect the AIRA Compact units to the same USB hub instead of separate ports
- Reduce the number of ground paths by reviewing your cable connections