Best 845 tube out there?

I am running a pair of Cary CAD-211AE monoblocks with the standard no-name Chinese tubes shipped by Cary. Whilst I am happy with the sound, I think I should buy a pair of 845's to keep as backup in case something happens to these tubes.

Because I will need to buy FOUR of them, this rules out any tube that sells for stupid money (e.g. vintage RCA 845 tubes).

The only current production 845's I am aware of are:

- Shuguang 845 "standard"
- Shuguang 845B
- Shuguang 845C
- Shuguang PSVANE 845
- KR Audio 845

I have found reviews of the Shuguang 845B and 845C, but there is virtually no information out there on the new Shuguang "psvane" 845. Has anybody heard this valve, and is it a noticable improvement over the 845B and C? Also, what do people think of the KR?
The major difference seems to be that the Psvane is far more extended at the frequency extremes,but at the same time has a far more richer harmonic presentation. Much like the qualities of NOS 845's

In comparison to the others, the 845T, right out of the box, seems brighter. After about 10 hours I began to notice a difference. Compared to the 845B, they seem far more transparent but at the same time much cleaner. Bass tones and pitch definition are improved. String tone seems to be more open and extended even more than the 845M,but at the same time more relaxed and natural sounding.
I always thought the metal plate 845 sounded etched and
unnatural.The 845B seemed to be a good all- round well balanced sound.

The soundstaging qualities are improved as well. Front to back layering and placement of instruments is enhanced more than likely because the sound is more open. Your definitely getting more info without any added brightness,at least once they are sufficiently broken in.
Don't forget to return here and update us on your 'post burn in' listening impressions, I'm sure many would be interested !
Just ordered a pair myself. I've had those glorious metal plate 845Ws in my SET monoblocks for the last 32 months but nothing lasts forever.
I have had a closer look at the Shuguang psvane 845T's. There is a very large image here:

Now compare that to the Shuguang 845B. The best image I could find is here: (the 845B is on the left).

Note the main difference - the Psvane 845T lacks the solid winged side support, and consequently has a plate at the top to stabilize the tube against the glass. On lesser 845's (e.g. the Shuguang 845), the mica top plate was criticized for causing microphonics.

Starting to have some doubts now.