Seabear

The most important thing is that you're wall wart is NOT putting out more than 13.8 volts. Some, though rated at 12V put out more than 15. The T Amp's chip will go up in a puff of white smoke (bad) if you give it too much juice.

If you have a multi meter you may want to check the output of your wall wart.

BTW, you get a bit more volume with more volts but 13V is just fine.

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.