G-log wrote:
Ok, I did some changes. I added one more 22uf 450V cap that supplies the screen node. I was using the Ceri@tone setup for caps(don't ask me why! ) That circuit uses one less filter cap than the Trinity 15,so now there are 2-33ufs and 4-22ufs . I changed the cathode resistor to 150R and now I get 8.27V at the cathode point,341 and343 volts on pins 7 of the el84s and 212V at the 100R junction node.Does this give me 8watts of power on the plates and 25mA plate current per tube? I am using the BBQ bias calculator to figure this out,it doesn't seem really clear to me I guess.So many variables!
Yes roughly 8W per tube, correct.
I am curious why your screen voltage is so low. What is the path leading up to the screen resistor?
Larger values for the screen resistor drop more voltage when the amp is being played hard and screen current increases. A larger value resistor will cause a softer sound with a bit more compression I have found. Worth experimenting if you're curious...