which way to start tube-rolling ? please

Go Preamp. the CD is just a buffer, no gain, little effect from tube rolling it.

-Ed

I agree with ED; however, what tubes are in the pre? Make sure that you know which ones are the gain tubes.

Having much experience with my Exemplar/Denon universal player, I would have to disagree with Ed about it being "just a buffer." This particular tube mod uses the 5965/6829/7062 tube. There are substantial differences with which tube is in the circuit, with the Amperex 7062 pinch waist being clearly the best.

I would Elevick as I think he is implying that only gain tubes need be rolled. I find rectifier tubes and other non-signal tubes can greatly affect the sound.

Your's is not the best time for beginning this as most of the old classic tubes are in very short supply now. About two years ago with great effort, I got 15 different pairs of 6SN7 tubes to roll in a Supertex Syrah I had at the time. I doubt if I could do this today.

You can hear some remarkable differences. Good luck.

I don't know about that one. When I went from Sovtek tubes to NOS in my Jolida CDP, the difference was astounding. In my experience, no tube change has been inconsequential. Quite the opposite, in fact.