Peter, Question about the TAD tubes used in Diezels

[guitarman967]

I was wondering if you could detail the differences between these TAD tubes I have Pictured. There is also a Ruby that was in the Phase inverter position of my VH4 when I got it..

There seems to be 3 different TAD preamp tubes.

The First one says 12AX7A-C Selected.
The second one says 7025 E83CC Highgrade. This one has me the most curious.. Is this supposed to be used in a particular position like V1?
The Last TAD says ECC83 Selected and has a much larger TAD logo. Is this the same as the 12AX7A-C or different?

is the RUBY a diferent Tube than these TAD's?
It says RUBY7025SS/12AX7A

Thanks so much for clearing this up if you can. I want to be able to use these preamp tubes to my advantage by puttin them in the best positions Possible. JOEL

 

[Peter Diezel]

The outer ones are 12AX7-C, same tubes from Shuguang
The inner ones are ECC83 made by JJ, former Tesla

 

[guitarman967]

Thanks for that info.I think I may have confused the issue though, Which one's are the Shuguang? The 12AX7A-C?
Is there any other differences besides brand that I should know?
Why is one considered a highgrade? Is it just marketing or is that a tube that has been tested more for gain and microphonics?

 

[guitarman967]

bump