The control knob of your Marshall Emberton speaker is located at the top of your speaker and it can be used for the following actions:
Power On / Off.
Push and hold for 2 seconds.
Play / Pause.
Push once.
Skip Forward / Back.
Push to the right or the left.
Fast Forward / Rewind.
Push to the right or left and hold.
Turn up / Down the volume.
Push upwards or downwards.