How?

Paging through Rob Robinette's (RR) amp and electronics resource website and reading hundreds of posts on several amplifier enthusiast forums and blogs (such as EL34 World), led me to the conclusion that I could, and probably should, just build my own. (1) It won't cost anywhere near what the equivalent item would cost me to purchase even second-hand, (2) I'll be able to voice the amp through the selection of components and circuit design to best suit my instruments and desired tone, and (3) I'll learn a lot and have fun in the process. 

I read through all of the relevant information on RR's site (multiple times), combed and consulted the forums, and referenced the schematics for all the amps folks were building and talking about, and I began to develop a sense of how amps and their circuits differed, and what I wanted to build. The general requirements  for my amp are:

• A 5F6A circuit architecture that is as close to the vintage design as is practical, as a head only (without built-in speakers)

• A second channel that offers something a little different soundwise, maybe  more JTM-like, for the input stage.

• Something that provides smooth high-gain tones, but that also provides for shaping and managing cascaded gain.

• Flexible channel jumpering and mode switching.

• Volume control in the form of a Master Volume - that is, a way to control the pre-amp separately from the power-amp part of the circuit.

• Enhanced tone shaping over what is available in the Treble/Mid/Bass controls typical for the 5F6A and JTM.

• Modern updates, like multiple speaker impedance selection, the ability to use different power tube types, adjustable tube biasing.

RR's site explains how to do many of these things, and offers a wealth of transferable knowledge that has informed my design choices. And though I arrived at many conclusions about what to build, I still felt lacking in some concepts that would help me understand WHY to choose one design over another, and how the heck to predict what's going to happen when I cascade one triode-amplified signal into the next triode.