any recommendations for a rich 6922 tube ?

i am buying a BAT VK D5 cd player. it has 6 6922 tubes.

i have no experience with this tube. my components use 12 volt tubes.

i suspect this is an old topic as many preamps and some amps use this tube.

nevertheless, some ideas as to a tube to replace the stock russian production tube to provide a more pleasant sound will be appreciated--hopefully not too expensive.