If a CD contains 700 MB of data and whatever "lossless" format takes out 30% of it. Even though the music quality is still pretty close, it does not surprise me that the 30% taken out translate into a perceptible difference.
Maybe on players like ipods... one cannot tell the difference because these were made for itunes and ipod/iphones devices, which are a lot less pure sounding than the Tera or HM801... but on a high end DAP, it is audible during quieter music passages.
Even Flacs that are supposed to be lossless, I can hear a background noise on the HM801.
True lossless does not take any data off an original CD.