UPDATE: This has less to do with Weber vs Mojo/others etc, and more to do with fine-tuning the 5F1 build/project itself. I calculated that my 6V6 was biased quite hot, and even though this is widely accepted nowadays in these single-ended Class-A Champ builds, I used four 5w 9v zener diodes on the PT CT ground to lower my B+ from 383v down to 350v and I like the results. Slightly less output, and slightly "better" overdrive/distortion. Now my 6V6 appears to be dissipating more like 12w instead of 14w+ based on some fast/loose calculations. Next I'm tinkering with the cathode bypass cap value on V1a, as well as choice of preamp tube. Currently using 10uf cap and a 5751 tube for a slightly more mellow/refined Champ, but I'll probably end up with NOS 12AX7 back in there down the road, as I want more of that classic Champ dirt. Just trying to dial out that boomy/farty parts a little bit. Might try a 4.7uf bypass cap next.