are all mp3 players created equil in regards to output level?

I'm a complete noob concerning mp3 players. I just assumed the output level would be similiar to that of a portable disc player or cassette player. I guess I asked the wrong question when deciding which mp3 player to get. I asked about sound quality not quantity. I bought a meizu 4gb mp3 miniplayer and although the sound quality was very good (especially for compressed audio files) it isn't very loud. I'm using some fairly efficient earbuds (102db) too.

so is there a difference between brands/models in regards to output level? I don't care if it is a little larger than the average. I want to hear/feel my music. tia.