[Jukebox-list] Re: A "shocking" 6L6 problem

On 10/17/23 07:48, David Breneman via Jukebox-list wrote:

So, just out of curiosity, since this is something I've been wonderingabout for decades : -)  What is the purpose of metal envelope tubes? Durability?  Shielding?  Conducting heat?

Ruggedness and shielding are the main advantages. Possibly a cost issue, not sure of the manufacturing costs vs. glass at the time.