Calculating bias voltage requirements

[clarkleach]

Is there a way to calculate the bias voltage required to run an output tube (or pair) at a given wattage?
If someone can create a spice model for a 6L6GC it seems like I ought to be able to crunch a few numbers and come up with a range of voltages to design a bias circuit around.
I've been searching the interwebz for answers and all I can find are regurgitations of ohms law.

[xtian]

Look at the tube data sheets. For example:

https://frank.pocnet.net/sheets/127/6/6L6GC.pdf

For Push-pull class AB, see given plate and screen voltages, and Grid #1 bias voltages.

Now, in practice, our amps usually have screen voltage much closer to plate voltage, and higher (more negative) bias voltages. But, hey, you asked for documentation.

[clarkleach]

Look at the tube data sheets. For example:

https://frank.pocnet.net/sheets/127/6/6L6GC.pdf

For Push-pull class AB, see given plate and screen voltages, and Grid #1 bias voltages.

Now, in practice, our amps usually have screen voltage much closer to plate voltage, and higher (more negative) bias voltages. But, hey, you asked for documentation.

That's not what I asked.

[Lauri]

It's easy to estimate it for 6L6GC class AB amp. You want your bias voltage to be about tenth of your screen voltage. So if your screen voltage is 400V, -40V bias voltage is usually going to be pretty close to what you want.