Tube curves

[merkur]

I'm looking for 6V6GT curves so I can trace loadline but the problem that I got is that only 250V for plate and screen are availlable.

Where I can find 400V 6V6GT curves for plate and screen?

Maybe there's a way of altering the 250 one's to make it 400V?

Any help will be appreciate!

Thanks

[SY]

Since the maximum screen voltage is 285V, it's unlikely you'll find 400V curves.

[merkur]

if you put about the same voltage on the screen you will be able to go higher.

Ex: Fender Deluxe 6G3 run Plate and screen at 375V

[cerrem]

Glad to see you are seeking the proper curves...

A couple things to keep in mind about screen voltage......
The screen voltage value you should be concerned with is the one you get at pin#4 when the amp is at FULL POWER OUTPUT...
Not the screen voltage at quiescent idle.....
For example lets say your B+ is 400V at idle....and your screens are roughly 398V, since they pull about 2mA at idle...
Now you apply signal gen and drive amp to it's Max clean sine wave output, right before any sign of clipping...
You look at your B+ and you might see 320V DC and you measure your screen at pin#4 and might see like 285V DC..... This is only an example....depends on the transformer and power supply capability, it's % regulation...
The reason I specify pin#4 is that you may have a screen resistor in line and this DC droop must also be accounted for....
If this is for a Hi-Fi application, then i suggest regulating the screen voltage for mucho improved linearity..... For guitar amp a bouncy screen voltage will give you more compression and grind....
Also note that the max voltage you can apply to plates is a function of the Class your operating in ...If you look at the data sheets, they typical list Max plate voltage under CLASS A conditions.... In Class AB you can safely run the plate voltages much higher, thats another whole story........
I will look around for additional data sheets...
What application is this amplifier...

Chris

[cerrem]

Here would be an example Load-Line of a 15W amplifier with P-P 6V6 Tubes....
Although the SCREEN is at 285V ....it may start out at 380V when it is at idle.....
Same with the plate..it might start out at 390V for example....
This graph represents the "drooped" voltages when the amp is at full power output....When no signal is applied, the voltages will go back much higher...

Chris