Battery light

[The devil]

I have noticed the battery light flashing on and off this evening and I am fairly sure the dash lights very briefly flicker at the same time.
Another thing that has been happening recently is the voltage protection circuit on the stereo amp keeps cutting in, maybe showing up a problem. Any ideas?

[Blu3R]

1st port of call would be the alternator for me. Usually the cause of failure is the rectifier breaking down which can cause symptoms such as you're having.