If you want full EVH tone, get Sylvania 6CA7's. That's what came in the block letter 5150's and why they sound different.
The Shuguangs that replaced them sound great, just not next-level like the OG real deal. They will absolutely do the job though and were also used in Rectos. My old guitar player had them in his 5150 and he sounded killer recorded, live and in the jam space.
If you're gonna go Sovtek, get the earlier production that have silver writing and just say "5881/6L6WGC SOVTEK USSR," or better yet get early 80's and older 6P3S-E wafer base. That's the real Russian military version of which the silver letter Sovteks are rebrands. The newer ones have black lettering and tig welds instead of tab in slot construction on the plates, which are darker with the real ones being lighter. They do not sound the same! Chatter suggests once Gorbachev got in, they sold the tooling to the Chinese and quality went down.
THEY ARE NIGHT AND DAY DIFFERENT TUBES. HiFi guys compare the legit ones to real Mullards. I believe this is why some people love them, and some people hate them. They are two completely different sounding specimens with the same name. I prefer JJ KT77's to the OG russkie but the OG russkie by leaps and bounds to the newer tig-weld "product." This is perhaps
the origin of Mike Matthew's tube name game.
His use of Mullard is tantamount to blasphemy.
How Mike and Soldano players aren't hip to this action is
beyond me!