[Isaacc7]

I saw that the Firebottle KT88 would set the screen voltage and anode voltage lower than the max rating of the el38 so I got some adapters and put them in. They sound phenomenal. But as I read more maybe they aren't a great fit and I'm killing them? Turns out that they require about half of the negative bias of an el34. I'm reading things like this, "EL38 has higher transconductance than EL37, and will require much less negative bias voltage under similar conditions."

I'm told to check if the plates are glowing red but I don't know which part is the plate. The entire inner section is lit up but I don't know if that is the filament or the plate. Wish I knew more about this stuff so I don't blow something up. I've put the 807 tubes back in until I can figure out if this amp is incompatible with the el38. Anyone have some resources I can check and see if running el38tubes is a bad idea? Dennis? Straitwire?