Glancing at the results, it seems like you didn't manage to hear a difference.
But regarding the methodology, I'll repeat what I said in another thread, just in case: you should use the same input on the amp (for example "CD") for both sources. Not all analog inputs are audibly the same. (Perhaps in theory yes, but I've had a case of an amp where an input was audibly different.)
Also, "Both sources was turned to the max volume (0dB)" does not guarantee that they were level-matched - you need to play some test tones and actually measure the voltage outputs of the CD player and sound card to make sure that they are really outputting the exact same level, as our ears tend to give preference to louder sources, even if they don't actually sound different.