Toobnoob,
Welcome to the forum.
I would suggest you get your basic tube circuit design foundation first. All other circuits are basically derived from the basic grounded cathode topology. This basic circuit will help you become intimately familiar with the NEEDS of any tube your working with. Here is a thread in which I propose a basic way of calculating tube voltage requirements for a grounded cathode topology. This is basically what the Zen Plate uses as a topology. Then I would further suggest that you get familiar with the cathode follower and how it works. Once you understand those two circuits many other circuits start to make a LOT of sense.
The one thing I borrow from the Akido circuit is ripple cancelation, but I use a white CF to accomplish this. To be honest I don't really understand why certain things are the way they are in the Akido circuit, what I have done makes a lot more sense to me and WORKS, so I am not worried about the Akido circuit and how it works really.
Here is a thread I started to help a few new to tube gents get their feet wet on tube circuits. If you know ohms law this should make things a LOT easier.
http://www.hawthorneaudio.com/forums/viewtopic.php?f=8&t=1784I basically find a Plate Characteristics chart for a tube I want to design with (enlarging it as much as I can on my screen), and then push my "print screen" button on my keyboard. Then I paste it in MS paint, and further cut and paste just the chart in a file all its own, and save it. I can go back and work out various load lines and how they will perform for me BEFORE actually breadboarding a circuit. This has saved me a LOT of time in working out the bugs of circuits. I was struggling with this for a while but kind of figured this methode out on my own, and it works real well. I imagine that others do something similar, or they may just do all the math without worrying about the load lines and how that all works.
One thing you will notice as you work with load lines, is that the higher the voltage of your B+ the more horizontal your load line will be, also allowing greater voltage swings with your tubes AC output, making it easier to drive many different power tubes. Often you won't need as much AC voltage swing as you will have designed a circuit to accomplish, but it can't hurt anything.
I hope this helps, any more Q's can be directed here or you can PM or email me for further questions. At the Audiotalk forum Eli Duttman is starting a DIY project of a single ended pentode circuit, you might want to follow that to see how it develops, it might help you gain more understanding as well.
TG
P.S. If you like me you will be disappionted with the education end of your venture into electronics. They teach you theory that may or may not be what you need to know later, and you will no doubt learn more from your work later after your education that will give you what you need to really know. I have learned more from other indiviuals on how to trouble shoot and design circuits than I ever did from school, but school gives you all the tools.