12au7 tube?

You want to go with what the cognoscenti declare to be the best of the best?

Telefunken G73-R. Love to try out a pair of those. 

+3 on Amperex. Sound wise it sits beautifully between Telefunken and Mullard.

Look for the 7316, the older the better.

+1 @audition__audio  about the clear tops. Annoyingly bright.

If you can find a pair of these, grab them. Westinghouse carbon plate 12au7, but a very specific limited production type.

So why this tube is not very well known? It’s very hard to find and even if you find it you have to be careful what you buy. The tube was produced by Westinghouse for a short period of time and after that was sub-licensed from RCA, which didn’t produce the same sound.

Here are the signs of the original WH 12au7:
1) Dots around 12au7 – not the GE type dots, but smaller dot’s in grayish color.
2) Getter must be raised on a copper post above the plate (RCA has them always attached to the plate). For of the getter is Large D with TWO (2) wires attached at the end (RCA only uses one)
3) Silver cover above getter is very extensive (RCA’s is much smaller). This makes it really hard to see the getter. I mean super hard – if you can see it easily, it’s not the real Westinghouse.
4) Plates are not shiny black like RCA, but carbon black. Very unique color – it’s not similar even to Ken-Rad of the same period. It’s like charcoal – a mixture of black and very dark gray. This makes it very hard to distinguish them on pictures – because the color depends on lighting.
5) Yellow color letters with number 337 for the manufacturer – if you are lucky to get silk screen in good shape.

Also with Westinghouse mentioned above, it has a printed 'V' over an 'M' in a circle, yellow in color. No idea what that stands for.

@tksteingraber ​​​​​, Yes, indeed!

The pair I have look like new. All silkscreen perfect, and I think I paid $35 for them about 4 or 5 years ago. Haven't seen another pair since.

Just a smooth, easy sounding tube.

Oh, and apparently the ’V’ over ’M’ stands for Voice of Music.

I think if they got the press Telefunken, Mullard and Amperex get, the price would go up 10 fold.

Wait, what am I doing??!

Terrible, terrible tube! 

I've got a pair of RCA 5814a JRC triple mica black plates. Nice tube.

Also have a pair of clear tops. Wouldn't take another pair if they were given to me.

Blacktops??

Do you mean black plates?

Can't win a prize if you don't buy a ticket!

They hide this in the FAQ on their site:

We want to give you the vacuum tubes you need. To achieve that, we work with multiple contract manufacturers across Asia and Eastern Europe. Because no manufacturer covers the entire range, each manufacturer specializes in different types of tubes. No matter where the tubes are made, each one goes through the same strict quality control process.

You have to go to Support, then hit FAQ.

Also this bit of dubious ’technology’:

Magic Coating is a monocrystalline carbon coating that improves sound quality. It cools the tubes, blocks unwanted noise, and speeds up electron transmission for a cleaner sound.

How it can do that when it’s coating the glass is beyond me.

Gotta admit, they have a good marketing department.

They also explain why their tubes are better than all NOS tubes which to me is a blanket statement of nonsense.