laptop to pa connection problem

[blake54]

hey guys, i am new to the forum and was after some advise. i have just bought a PA system and a laptop and want to get into some dj'ing (i was thinking of using virtual dj unless there is a better program out there). however when i connect my laptop to the amp there is a ringing noise in the background when i play mp3's do i need a good sound card to fix this problem? when i hook up other devices to the system there is no ringing (ie a dvd player) so it's something to do with my laptop/soundcard. my laptop is a Benq R55V40 Notebook. nothing is modified, but i bought an internal hdd with a case to make it external. any advise would be appreciated.

[Splash]

Can you be more specific as to this ringing sound? Also what bitrate are these MP3s?

[dave87]

Have you tried using the laptop without the mains adapter plugged in? Does the buzzing sound still exist?

[blake54]

actually i think dave87 may have helped. when i unplug the power supply the noise isn't there. i haven't had a chance to fully test it because it's 1am in australia and i don't wana anoy the neigbors but i'll test it later. if that is the problem is there a something i can do to keep the power supply connected but not have hte noise? thanks

[herulach]

the noise is interference due to problems in the power filtering. the onboard sound on my board would make a clicking noise (like an iPod) only audible when i got my decent headphones.

An external soundcard of decent quality would likely solve your problem, as running on battery power isnt really a long term option i wouldnt have thought.

[blake54]

thanks for your help guys