Id argue that your source should provide an accurate and reliable representation of the information on the disc -- at least that's my opinion. Some tube CD players, such as the Jolida JD100, use solid state op-amps for the analog output sections, then they add a couple of tubes as a "buffer" stage, in effect using tubes as a tone control.
That said, CD players do sound different (duh!), and some are warmer than others. On the warm and musical side are the new Naim CD5i-2 (the new version, not the original CD5i, which is sharper and brighter), the Rega Apollo or Saturn, and, less expensively, various Arcam models such as the CD73T (full disclosureI have an Arcam for sale on Audiogon).
That said, CD players do sound different (duh!), and some are warmer than others. On the warm and musical side are the new Naim CD5i-2 (the new version, not the original CD5i, which is sharper and brighter), the Rega Apollo or Saturn, and, less expensively, various Arcam models such as the CD73T (full disclosureI have an Arcam for sale on Audiogon).