6922 Recommendation for my BAT VK-3iX Preamp

I run Siemens CCA grey plates in my BAT VK300x. SWEET !!! A NOS pair will set you back about $200.

I suggest Amperex US 7308 PQ White Label 60's, my reasoning is:
This is a quiet well balanced tube by design.
It presents hi's, mid's and lows evenly.(well balanced)
You can try them for a reasonable price.
You will hear your system through this tube.
By starting here you'll have a good idea where to go if it doesn't do it for you.
If you find you want more mid fullness you can go to Phillips Holland 7308 60's which is fuller in the mids etc.........
For more detail(less warmth also) Seimans CCA's etc...........

With the Siemens CCa's(pre 1969 ONLY- the later CCa was extremely strident), you will hear the music, not the system. Transparent, extended in both directions(without bloat of glare), liquid midrange, excellent imaging and soundstage. They were a tube specially built, tested and selected for silence and durability(10kHr) for the German Telephone service. Telefunken E188CC/7308 tubes are also very transparent(no added warmth or microphonic colorations). Of course- Some enjoy the "tubey", "warm", "sugary" colorations of British(Mullard, Brimar, etc.) tubes. The Amperex Company made some nice tubes that fill the middle ground. Be certain that whomever you purchase tubes from tests and certifies them as "low noise/preamp grade" tubes. I've got six CCa's in my BAT VK-D5, but- everyone must satisfy their own tastes. Happy listening!

in what way do you want to improve the sound, violin in particular? What's missing right now? How does it sound when you play violin music? Be more detailed.

I'd like to hear more texture and harmonics in the midrange. A friend brought his highly modified tube preamp over and played it in my system. There was more magic in the mid range with his preamp. But it lacked dynamics and extensions....

I would try Amperec tubes, but I'm not sure how much of an improvement in this area you will gain with a different set of tubes.

But I think you will get what you want with a different preamp. Swapping tubes may be cool, but I kind of doubt it will be a long term solution.

Very thoughtful posts....Rodman has got it pretty much dead on.Particular tastes will determine the final outcome,though.

Best advice-----Experiment!

Good luck

Another thought. You might consider using 7DJ8 tubes, basically a 7 volt rated 6922/6DJ8. Some circuits may not be compatible, but I've never encountered a problem with the substitution. The construction of the two tube types is supposed to be identical. The prices on primo 7DJ8s are also about a quarter of what you would pay for a comparable 6DJ8.