Hello and Welcome to the forum!
I have a TA-30 and also it has quite a bit of hum. I am thinking about replacing the tubes, including preamp tubes. I am not sure if it will make a big difference, but Mesa sells low noise substitute for the 12AX7:
Hello, I am new to this forum, and this is my first post. To make the story short, I bought a second hand TA-30 Head (my first Mesa branded amp), that I have linked to a Bogner 2x 12 cabinet with Celestion speakers (G12 H30 Vintage series 30 watts + G12 Blue Alnico 15 watts), and it was working...