I realize now that I am doing the wrong thing with the 6F8G tube. I am an old man and sometimes get things a bit confused although my hearing is good. I have been using the 6F8G and the 6C8G this way for about 6 months and sometimes have left it on for weeks at a time. I have experience no distortion - in fact quite the opposite. I have many 6080 and 6SA7 tubes and have experienced better sound with the 6f than any of these tubes. I will quite using it in this manner as I do not wish to damage the tubes or the amp. Thanks for the helpful information, JS
