"There are no more stocks of the 6C45Pi EH Gold Pin available. There should not be a difference in the sound signature. The Sovtek 6C45Pi has the same specifications as the gold pin version. The EH Gold Pin version are actually Sovtek 6C45Pi that had the pins gold plated."
That is the email I got from the maker of EH and Sovtek tubes in Russia. Take it for what it is worth but if anyone knows the difference should be him. Apparently the two tubes are identical except the pins are plated expecting no difference in sound signature. Placebo effect? Anyway I ordered 6 backup pairs of the EH from Woo just incase as I have scoured every resource I could find to hoard the EH tubes for my own future listening pleasure. Having that tube failure opened my eyes to what might happen if I don't hoard them. Seems Woo is the only one who has them left in the world perhaps. Was this by accident? ;)