It's my new build. I think I may have fixed it by putting a 470pF across the cathode follower. But I'll have to test it some more.is this an old Marshall or your new build?
That essentially sets up a low pass filter, probably just masking the issue which is still there.It's my new build. I think I may have fixed it by putting a 470pF across the cathode follower. But I'll have to test it some more.
Have you dialled in your bias at idle. What are the readings?It's my new build. I think I may have fixed it by putting a 470pF across the cathode follower. But I'll have to test it some more.
Yeah I’m thinking the same thing. Bias related. Or grounds/solder joints related to the power tubes.Have you dialled in your bias at idle. What are the readings?
Check the grounding on that 3k3 resistor and 0.68uF bypass cap.Thanks for the responses. I haven't had an opportunity to contine testing over the last few days. The bias is set to 35-36mA. Clipping is not engaged. That clip is very low MV. Maybe between 1 and 2?
And this only occurs when I have it switched to the JEL mode. It doesn't happen in the stock or the #34 mode.
How do you mean? I have them on a 3 way switch like this diagram. I'm using a 0.22 cap instead of 0.47.What order did you put the diodes in?