The Alva ST comes set up with Auto Power Down (APD) enabled, and will automatically switch to standby mode after 20 minutes of inactivity.
To disable APD: Press and hold the power button for 5 seconds when in standby.
To re-enable APD: Hold down the power button when plugging the mains power cable into the turntable.
Note: APD is automatically disabled when Phono output is selected.