effect of tubes in cd players

I had the opamps changed in the Cayin 15 to wonderful effects. , the 15 which offers ss and tube outs. The bass is a tiny bit more pronouned through the ss, but the mids and highs are superior in the tube out. So thats how I listen.
My Cayin 17 offers only tube and am in the process of making my final tweak, changing the caps. I'll post a note on the results.
Makes sense to me that cahnging the cheap stock caps with mundork M series (not their best , not the cheapest) would affect the sound, as the caps is the very last stage that the sound passes before it exits the cdp.

I agree, some designs will be more sensitive. My Cayin 17 showed enough improvement over the stock tubes to justify the 175.
I have plans for upgradeing caps next

I agree with OZ, there's A-Z qulaity tube amps. A well designed/high quality parts tube amp will exceeed most every ss amp. We are talking musicality and also fatigue factor. I could never go back to ss amps.
back to "small differences in tube rolling". There is a point to be made that in some tube amps, the design (or is it also parts quality) is poor, and so has this 'signature sound". So no matter what pre tubes you use tthe difference will be over rided by the 'sig sound' of the amp. Now driver tube replacement will obviously be a greater cahnge, but the cost factor is high.
I wouldn't roll expensive tubes in a poor design tube amp.

back to the original question. "Does tubes inside a cdp make a differencea as say in a tube preamp?"

Yes the tube out on my Cayin 15 sounds to my ears more airy/musical vs the ss outs.
"small" but still noticable.

The tech guy here in baton rouge said of the layout in the Cayin 17, dual power supply, true dual balance stages, 4 6922 "I'm very impressed what Cayin has done in this player".
For the price its the most impressive looking, and finest built player for under 2K.
You can write to him and get his opinion.
Paul
Baton Rouge