Tripping Breakers

I had a similar problem some years ago and it was, in fact, the breaker that had failed. It's cheap and easy to replace the breaker so that's certainly something you can isolate as a potential cause of problem.

Try plugging the amp into another circuit. If the same thing happens it may be the amp or power cord. If it powers up successfully and your breaker doesn't trip then the breaker on the circuit you usually use should probably be replaced. This is not unusual as breakers age, as most people above have pointed out.

Are you sure that you did not add a lamp or some other electrical consumer to the circuit? I was having a similar problem until I put in dedicated lines. In another room every time my wife turned on a few lights, I threw the breaker because I was pulling to many amps.

Here is to dedicated lines and great music.

The breaker is a good choice. Also if you are using the "thin" style breakers, (these are the ones that fit two to a socket) they will work poorly. If it is a GFI type breaker they work poorly and die frequently. You may have to try more than one replacement to verify the breaker problem. When installing our spa the first two from the local Home center ran hot, emitted a stench and were down right scary. I had to go with one from an electrical distributor and it has worked properly. Beware of cheap junk.
Good luck, John

I agree with all of the comments on aging circuit breakers. I have both been there and done that. But I also have to add some potentially worse news. I have noticed occasions where a buss bar became burned and continued to be a problem after the breaker was replaced.

Definitely replace the breaker with the best one you can find but also take a good look at the buss bar. I am not sure what brands of breakers are best. For my old house I am just thankful when I can find one that is the right style. Good luck.