Qobuz vs Tidal is there really an SQ difference for CD quality?

If both are from same master, then it should technically sound the same. Across the board, CD quality are actually down-sampled and some are sampled rate to 44.1k from Hi-Res masters. The only difference you will hear is Tidal Masters vs Qobuz Hi-Res; even both are derived from the same masters, Tidal Masters goes through an additional MQA processing. In a good quality setup system, one can perceive SQ difference.