To check if your devices are connected properly, read below:
First, make sure that the iPad is connected with Apogee microphone and an earphone is connected to Apogee microphone.
If the microphone is connected properly, the led bulb on the microphone will be light up in green and display the volume level.
If the microphone is not connected properly, the led bulb on the microphone will be light up in blue. You can try reconnecting the cables or restart iDub.
For extended recordings, you can recharge the battery while recording by using the USB Hub.