Tube stage for CD player output

Dear community,

I've been recently working on my AMC CD9 player in which I first swapped the 3 stock NE5532 dual opamaps with Burson V6 vivid. Great improvement indeed.
Then I started looking into tube stages and played around with a couple 6H6P tubes (as suggested by Lampizator) and the following configurations:

• Differential ground-cathode (slightly better audio performance than Burson)
• Differential SRPP (slightly better audio performance than Burson)
• Broskie cathode follower (not as good as Burson)
• Differential anode plate follower - on two different bias points (on par with Burson)
• Differential anode plate follower + cathode follower (on par with Burson)

So far I would prefer the SRPP configuration though the improvement is only incremental...no wow effect.
Can you suggest any other configuration or tube set (I have space for 2 tubes only) worth trying?
Thanks!
Fabrizio