CJ DV2b CD Player - Tube Ideas?


Has anybody tried tube rolling with a Conrad-Johnson DV2b CD player? (It uses 2 - 6GK5 tubes)
Thought about trying Mullards...as always - looking for more "vinyl" out of a CD. ;-)

Thanks, in advance, for any input.
I used to own this player and the Mullards sound very nice. The 6GK5s are relatively inexpensive too.
Thanks for your input Mchd1.
Would I need to be worried about 2 matched tubes, or would "healthy" tubes be effective in this application?
I am open to other tubes, but Mullards seem to be known for their "analog" sound.
Thanks again.