How to read "Typical Characteristics" curves

[pforeman]

Could someone please explain what I'm looking at when I look at the curve plots of the tubes when I go to a Tube Data Sheet site.
I have a simple se and was just wondering what info I'm supposed to glean from these curves.
Not only how to tell what I'm looking at, but what would be the ideal curve,etc.

Also, When i read the tube data sheet info for Triode connection, I see specs for: DC anode and screen voltage and current. ???does this pertain to someone (like me with a simple se)
Thanks,
Paul

 

[TubeMack]

That subject would take an entire book to explain, so from Mr. Millets fine online collection.


http://www.pmillett.com/Books/rider_inside.pdf

Lots of info on this after the first hundred pages or so.......

 

[rotaspec]

Could someone please explain what I'm looking at when I look at the curve plots of the tubes when I go to a Tube Data Sheet site.
I have a simple se and was just wondering what info I'm supposed to glean from these curves.
Not only how to tell what I'm looking at, but what would be the ideal curve,etc.

Also, When i read the tube data sheet info for Triode connection, I see specs for: DC anode and screen voltage and current. ???does this pertain to someone (like me with a simple se)
Thanks,
Paul

I am a relative neophyte with tubes, so I can agree with TubeMack that some background reading is essential before you can appreciate what's in the tube data sheets.
Without going into specifics about a particular output tube in the Simple SE, triode connection will mean effectively that the anode and screen are connected together and therefore are at the same voltage. That simplifies things because (within the tube's limits, usually the max screen voltage allowed) you can ignore the screen altogether and the characteristic curves become similar to an actual triode tube. That allows you to compare your choice of pentode tube (which now is acting like a triode) against real triodes that have similar characteristics.
So try to answer your last question: It will be helpful for you to know what you are looking at if you want to try different tubes in the SimpleSE, or try the same tube in triode connection, or to find out if that tube you just picked up at an auction will work (or how well).
Tube characteristic curves will tell you (once you learn how to interpret them), how the various components that you see surrounding each tube socket on the PCB were chosen for a particular tube. From those plots you will be able to choose your own components to support the tube that you may have picked up at the auction above that looks like it will fit in the same socket connections. George very cleverly designed that PCB so that the builder doesn't NEED to know these things, but if you want to change to an unsupported tube or are just curious why some tubes are good for amps and some are not, then an understanding of the data sheet graphs is essential.
Everything from the tube that feeds it, to the output transformer electrical parameters and the ratings of the power supply, is chosen based on the tube characteristic curves.

Gary