Re: Re: AX84 Variable Bias

[DeepBlue]

So I have a new question/problem. I am fairly sure I am measuring everything correctly and my specs look fine with the voltages all being withing very close to spec to the SEL schematic. However when I calculate the power across the bias pot it seems to be fine, about 1.4 watts for a 3watt pot, but after a few hours of playing I notice my master volume pot becomes scratchy and begins to cut out at higher volumes. At the same time that this scratchy noise appears in the Master Volume, the bias pot appears to become stuck? I am not sure if it is overheating and melting? It seem to be fine in terms of the power it has through it? I am measuring the voltage drop across pin1 to 3 on the pot? Is this in correct? Has anyone else had this problem appear and maybe have any suggestions? I at first thought I had a scratchy volume pot, but after replacing the bias pot, since it became stuck, I noticed the scratch was gone, and sure enough when it appeared again the pot was stuck again.