• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Triode/Pentode Loadline Calculator

Well many thanks to gsmok!

I happen to have a gm100 based amp and can confirm that I use it at 0v bias (or something tad higher than that like +16v according to room temperature).

I never ever used +55v on the grid which would burn my opts 100%.

is there a way to set bias point?

personally I am running 250mA per tube (hammond 5k 300mA OPTs)

Many thanks!
 
When are you planning to include pentodes?

The pentode model has long been implemented (it is temporarily locked.). The problem is with the availability of pentodes data - anode characteristics for different screen voltages. Manufactures data of interesting tubes include characteristics for only one or two screen voltages. In order to smoothly change the screen voltage more data is needed. Well, unless we abandon the free choice of the screen grid voltage. I'm still looking for some good sources of data for pentodes.

I've added all of the tubes mentioned in previous posts to the list of additions.
 
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The pentode model has long been implemented (it is temporarily locked.). The problem is with the availability of pentodes data - anode characteristics for different screen voltages. Manufactures data of interesting tubes include characteristics for only one or two screen voltages. In order to smoothly change the screen voltage more data is needed. Well, unless we abandon the free choice of the screen grid voltage. I'm still looking for some good sources of data for pentodes.

I've added all of the tubes mentioned in previous posts to the list of additions.

Would be very interesting to present the pentode results on 3 axes -- instead of lines you would have planes.

Anyone with u-Tracer could provide pentode data.
 
The pentode model has long been implemented (it is temporarily locked.). The problem is with the availability of pentodes data - anode characteristics for different screen voltages. Manufactures data of interesting tubes include characteristics for only one or two screen voltages. In order to smoothly change the screen voltage more data is needed. Well, unless we abandon the free choice of the screen grid voltage. I'm still looking for some good sources of data for pentodes.

I've added all of the tubes mentioned in previous posts to the list of additions.

If you're still adding stuff to the list, it'd be cool to see the 6AS7 in there 😀.. I have no idea how much work is involved for you to add tubes, but if you're up to it I'd definitely appreciate that!