Check to make sure that the amp is turned on first, then turn on the app. Also, if you use an app that determines chords in a song, like Chord AI, you can turn on Chord AI first on your phone/iPad, connect the amp to your device, turn it on and load the app. Then you can hear the song playing through the amp or headphones as you play. If this is out of order it won't work. It works on my Spider V20 mkii.