I'm getting ready to get into amp building. I've spent considerable time reading up on the subject, and I'm getting ready to build something resembling a 5F1/5F2A Champ/Princeton. It's easy enough to identify a whole bunch of compatible PT's and OT's that will do the job. However, I am leaning forward to my next project - a 5E3 type - and realized I can probably buy these transformers carefully and slightly overspec'd, thus preventing me from having to rebuy when I decide to tweak/redesign for potentially push-pull or SE EL-34/6L6 designs. So, I've narrowed down a couple of potential transformers: PT: 370EX OT: 125ESE I picked these because they seem to be usable for a variety of circuits. However, I get conflicting info on the 125ESE; it's optimized for single-ended class A, yet some seem to indicate they've used them for class A/B push-pull. These are the types of things I'm concerned about. I'd really like to be able to buy a single set of transformers and get alot of flexibility. Anyone tried this? Are there better transformers for what I'm trying to do, and can handle everything from SE 6V6/EL84 to push-pull 6V6/EL84 and up to a single tube SE 6L6/EL34/KT66 design? Or should I resign myself to buying multiple transformers? Thanks!