your jpcsp is ancient, upgrade that first.
http://buildbot.orphis.net/jpcsp/index.php
and if you can't use sonicstage, you won't be getting a lot of the sound. the at3+ format is still not understood completely and relies on outside decoders like sonicstage or atrac3plus2wav.
if you've been trying with sonicstage's online installer, that won't work anymore. you need an offline one for that. to download it, and also for some info on how to set up atrac3plus2wav, go to http://www.emunewz.net/forum/showthread.php?tid=14984 under "JPCSP and sound"
http://buildbot.orphis.net/jpcsp/index.php
and if you can't use sonicstage, you won't be getting a lot of the sound. the at3+ format is still not understood completely and relies on outside decoders like sonicstage or atrac3plus2wav.
if you've been trying with sonicstage's online installer, that won't work anymore. you need an offline one for that. to download it, and also for some info on how to set up atrac3plus2wav, go to http://www.emunewz.net/forum/showthread.php?tid=14984 under "JPCSP and sound"