Too bad that the device has such a Spartan manual. With some experience and try to get though to all features, but still. False is the information that is to be selected to select USB as a source S-Card. About the Source button only to switch between CD and Radio is possible. To select USB, you must press the USB button on the remote control in CD mode. Then it takes a lot of patience until sometime "Load" appears on the display, then "Stop" and then the first track begins on the USB stick. He searches all folders and assigns the mp3s to play alphabetically. Leg AUNA unfortunately find no Downloadable manual, thought as I find a better one.