I have 2 2001rb's. My first one does pop when powered up and my second does not. The first one's clip light also blinks on for a sec when it is first powered up. I've never had the issue looked at.
All SS amps give some noise as they power up or down. This is perfectly normal. Most amps have a delay on, instant off for the speakers jacks minimizing the noise that gets through. This is the audible click you can hear a few seconds after power on.