The music player on the phone also has a built-in equalizer with several pre-sets to fine-tune the music being played. Software The bundled version of the Nokia Audio Manager software was designed to encode music and transfer it to the phone via USB, but encoding would typically take several minutes per song and the software only ran under Windows. The design was that files encoded and transferred to the device could not be converted back to their original formats for playing on other devices. However alternatives to the Nokia Audio Manager did exist, such as Nokryptia, a cross-platform command line tool distributed as source code which by exploiting a special case of the Lockstream Embedded file format could convert MP3 audio files almost instantly to the 5510 playable Lockstream Embedded format. Nokryptia worked by prefixing the MP3 file with a special header that then allowed the MP3 to follow unencrypted (the tool also supported the reverse, removing the header to restore the original MP3 file, however this was only possible on files encoded by the technique and the tool could not restore a file encoded by the Nokia Audio Manager). References External links Nokia 5510 - Product info 5510 Mobile phones with an integrated hardware keyboard Mobile phones introduced in 2002 Portable media players