[heyheykuk]

Hello, i got a question.
My friend is giving me his ibasso d4 mamba amp/dac in a week, so does the sound quality from the mp3 player matter if you have that amp ?
sorry for my bad english

 

[Mad Max]

Always.
Rolling opamps in the D4 can help you tailor the sound more to your liking.
You can use the DAC with a laptop or desktop computer.
 
Edit: I should clarify, the better your player, the better the sound.  Using your player's line-out, if it has one, is a little better, too.  Ultimately, your headphones and your player will have the most impact on the sound.