5e3 kit - 6v6 pin 1 to pin 8

[6v6Pin1]

Why does the layout show pin 1 connected to pin 8 on the power tubes? As I understand, pin 1 is unused. What is the benefit of connecting these pins?

[sluckey]

Maybe some day you will plug some EL34s in the amp. That's the only time you will need that connection.

[PRR]

With metal 6V6, pin 1 is the metal shell and should be bonded to chassis.

I have never seen a metal 6V6, though I have seen one picture. I did know a lot of metal 6L6, but that was a long time ago, and 6L6 is too much for that amp. A true 6550 has a metal base which should be bonded to chassis, but that's way too much tube for a 5E3.

Yes, or EL34, which has G3 on pin 1 and should be tied to low/zero voltage.

If you tie pin 1 low, do NOT run 7027. (Unlikely you would, or that they would even fit a true vintage size 5E3.)