jolida jd100 and rca command tubes


I recently replaced the stock chinese tubes in the jolida with the rca command 5751. I was expecting to hear significant improvement in sound but did not. Has anybody used these nos tubes in this cdp and how did these tubes sound?
jund
I have given the rca command some 50 hrs or so burn in time and have noticed improved sound in both depth and details. Despite this I succumb to the urge of trying other tubes, not nos this time and see how they compare. I have just placed an order for eh gold pin 12ax7eh. I have heard good stuff regarding these in this player. Has anybody else compared these 2 tubes(rca command 5751 vs. eh gold pins 12ax7)?
I finally got the eh 12ax7eh gold pins and allowed at least 50 hrs burn in time to judge them. I thought they definitely sounded better than the stock chinese tubes the jolida came with but not superior to the rca 5751 command in terms of smoothness and depth. The rca's are still to my taste getting better and better each time I listen to them, so they are the keepers for now.
Sometime back I compared RCA blackplate 5751s, the EH 12ax7s, and EH goldpin 5751s. I preferred the EH goldpin 5751s to everything (there were many others) except Telefunken 12ax7 smoothplates. For less than 40 bucks I strongly recommend trying EH 5751s. But.... the keyword is "trying." What worked for me and my system may not for you!