Tube rolling experts!!!


Hi guys,

I am looking for advise based on your experience with these particular tubes in my components.  

I own a Raysonic CD128 since 2009. The player came with 4 Russian 6922 EH tubes. I don't know what's the average life span of tubes or when they start to deteriorate from their optimal performance. The player is used sparingly, may be no more than 500 hours over last 7 years. Is it time to replace stock tubes?  

The second components is Modwright Elyse with Phillips NOS 5R4GYS Rectifier and Tungram PCC88/7DJ8. Is there anything else out there that I can experiment for substantial boost in sonics?

I am after that lush midrange and extended top end. More air around the instruments, but stay away from anything that overly 'bright'.  

The associated components are Krell Evolution processor and Modwright KWA150SE (both solid state). 

Thank you for your time!
128x128lalitk
Thank you all for your recommendation. I will ordering some of these tubes and try to have some fun! 
I have the Phillips 5R4GYS and Telefunken E88CC's in my Elyse and love the combination.  I did have to send my Elyse back for an issue which was fixed, I included the Telefunkens which Dan compared in his lab, his comment was they are very good.
azbrd, so far 2+ on Telefunkens. I am sure they are every bit good but also expensive. Just as much as Phillps miniwatt SQ. 

Thank you! 
I have had the Raysonic cd128 for about 5 years, never changed the tubes, the guy I bought it from had already upgraded tubes (philips) so I can not compare with original stock tubes.

A big change happened for me, when I swapped out the standard power cable to a Shunyata Alpha Digital.

Please could you advise, when changing tubes for RCA do you change all four tubes?