Tube Suggestions 6922 4 pathos Classic one

Pardon my ignorance, but it is the first time I hear that instead of the 6922, a 6H23 tube can be used. What is the origin of this tube, I mean, what manufacturer and date can be considered NOS....the first time I heard of this tube is that it was being used in some BAT gear, I thought it was a sort of super tube, usually made in the old Soviet Union or something. If this is the case, what are the advantages of using this tube instead of the classic and now, almost non existant stock NOS 6922 and EC88s?

You should look up "Joe's Tube Lore" over on the AudioAsylum FAQ. He's goes into great detail on the 6DJ8 family of tubes. I have found his observations to be reliable. For a warmer sound you could try an early '70s Siemens 7308. They aren't as pricey as early CCa versions and would give you a taste of the 'Siemens' sound; warm, larger images, softer focus.

I disagree with John_tracy, Siemens are not warm sounding tubes. Compared to Amperex's and Mullard's, the Siemens sound leaner. That doesn't mean that the Siemens sound bad, mind you.

When I had my version 2, I found the 6dj8 amperex's to give the best soundstage/imaging/bass, plus I have a ton of them for pretty cheap if you need some, both NOS and like NOS.

I have tried mullard/siemans/amperex ect and found the amperex to give the best sonics for MY EARS.