I need some advice on tracking down a source of buzzing. I have been get buzzing from one channel after about 45 minutes of use. Today the buzzing started, as usual, at the 45 minute mark but was only intermittent. It would last for about a minute and then go away. I am now at 75 minutes of use and all is now quiet.
I have switched tubes and reheated all solder joints but no luck.