Sony Ericsson K750

There is one more button on the device, which is located on the top of the left side when the phone is held vertically. This button, which is located where the volume control has been on past Sony Ericsson handsets, is the dedicated play/pause button for music. At the bottom end of that same side of the K750 is the memory card slot, which holds Memory Stick Duo Pro cards that are currently available in sizes of up to 2GB (and theoretically should be able to go as large as 4GB in the future).

The phone has good all-round support for many versions of the MP3 file format, however support for WAV encoded files is not as extensive
AAC support is good, but the phone can only properly handle LC AAC. HE-AAC (aka AAC+, aka eAAC) will play since HE-AAC is designed to be backwards compatible, however the SBR component will be ignored. The same is true with HE-AAC v2 (aka eAAC+), only the normal LC component of the file will be played. The SBR and parametric stereo (introduced with HE-AAC v2) is ignored.