MP3s are awfully convenient, but they’re also awful when it comes to audio quality. The differences are painfully obvious when compared to a proper full-fidelity uncompressed recording. (Engineers: Do NOT tell me it’s all in my head. I’ve done plenty of blind A-B testing and I know what I hear.)
A number of scientific types are working on ways to make compressed digital files sound better using an external gadget in the soundchain. One such gadget is called the Encore mDSD. For $99 USD, it might be worth it. Learn more here.