I am looking at building a ~80W class A amp for experiance and to save costs. I am looking at the AE Aegis One's (nice kit for about $500 here) to couple it with for now but eventually will go up to ...

You could buy a cheap amp for $140, like I did. I got a Pioneer VSX D209 for that, with sales tax 6.5%. Sounds decent too.

A conventional tube amplifier has a circuit whose fundamentals were well in place around a hundred years ago, so there are few surprises to be found in building one today. Nevertheless, building one ...