I feel the need to interject, and not just because you corrected my spelling.
A quick search on Google reveals that the Onix is an OEM by Shanling. Shanling is well known for producing preamps, amplifiers, and CD players with tubes. If the company's goal is to produce "warm" sounding electronics it's quite simple to design a CD player that would emulate the sound of a tube line output using a transistorized configuration (Bob Carver achieved this on his amplifiers only on the input stage).
It is no stretch to assume the Onix would sound different from most CD players, as does the PlayStation 1 video game system released by Sony that a few audiophiles claimed was on the level with some 5K CD players because it had a mellow and warm sound signature to it. The Playstation 1's intention was not to be a CD player, therefore linear output was not a requirement. It's quite possible that the Onix CD player was made intentionally to be non-linear making it have a distinct sound signature which some might like better than the flat response of basically any other CD player that was designed to be accurate.
I try to watch out for those intentionally non-linear CD players and other devices, since they are not accurate. I have no use for non-accurate source components, preamps, and amplifiers. I've got a enough trouble on my hands trying to get speakers that are linear, and getting room acoustics to go with it.