Just to be clear, latest posts WRT heater are for > design loads.
Don't want anyone popping in to thread now to think they need to change anything other than C3H to 330uf
unless they want to support tube heater loads higher than CTH was designed for.
IOW,
my C3H revision guide stands for CTH target tube loads. And @ those loads, no other changes are necessary (ICH heatsink is NOT required, but does no harm).
Keep in mind the CTH "design center" is 12au7 variants and
the design heater capacity supports 90%(?) of the tubes that could possibly be plugged into the CTH... Heater tweaks above the basic design may let it support tubes further away from its design center & that could be fun.
So if > 600ma (4W) series tube heater loads
can be supported through some tweaks (the focus of these latest posts) maybe the tweak can make it to the CTH tweaks page when ready. Such a tweak may require switcher heatsink in tight quarters, etc.
Have fun gentlemen
