![[-]](https://theultimatetone.com/images/collapse.png "[-]")
06-01-2023, 06:33 PM
I see what you are saying. Ground in these terms is a reference point relative to another point in the circuit but not the actual chassis?
The good news is I got the bias working again meaning it changes. With 2X150R in series = 300R cathode resistor the current draw starts at about 22mV. The current at the test points go higher as I adjust it. I have it wired as in the pdf now. I took the ground wires off the MV pot "o" now. The only issue now is as I adjust the bias pot up in current the volume increases so basically its as if the reference to ground is shifting. So the physical MV at zero is not zero.
The tubes in question seem to be functioning now. It's strange. It wasn't before. But I put in new el84s and it wasn't "running" away. So I put in the previous tubes back in to confirm they are toast but they didn't either. Anyways I will draw up a proper layout that is cleaner than the previous hand written one. I just found out Diylc software.
The good news is I got the bias working again meaning it changes. With 2X150R in series = 300R cathode resistor the current draw starts at about 22mV. The current at the test points go higher as I adjust it. I have it wired as in the pdf now. I took the ground wires off the MV pot "o" now. The only issue now is as I adjust the bias pot up in current the volume increases so basically its as if the reference to ground is shifting. So the physical MV at zero is not zero.
The tubes in question seem to be functioning now. It's strange. It wasn't before. But I put in new el84s and it wasn't "running" away. So I put in the previous tubes back in to confirm they are toast but they didn't either. Anyways I will draw up a proper layout that is cleaner than the previous hand written one. I just found out Diylc software.
