what can i do in the audio stages ?

[grahamdvddvddvd]

I have made a hang on the wall jukebox with a Dell GX270 pc and elo touch screen monitor, everything was great untill I turned on my amp which is built into the cabinet a small 12 volt amp its only used for basic stuff as it has line out to my main amp this is the amphttp://cgi.ebay.co.uk/Car-Motor-bike-Stereo-Amplifier-Amp-Hi-Fi-2-x-180W_W0QQitemZ350189343109QQcmdZViewItemQQptZUK_Au dio_TV_Electronics_In_Car_Entertainment_GPS_Car_Am plifiers_PP?hash=item350189343109&_trksid=p3286.c0.m14&_trkparms=72%3A1689%7C66%3A2%7C65%3A12%7C39%3A1%7C 240%3A1318 Its picking fan noise up and if you use the cd drive it picks the motor noise from the drive up ! what can I do and can you buy an audio card with built in amp ?

[Luke122]

The most common source of audio noise through an amplifier is your ground wire. Have you put this amp inside the computer, or is it using the computer power supply? If so, try connecting it with an external power supply (like a standard "wall wart" plug) and see if the noise is still present. If so, the amp itself might be faulty.

[Luke122]

Also, the connection you used from the output on the computer to the input on the amp might be faulty.. have you tried other connection cables?

[grahamdvddvddvd]

Hi all thanks for your replies, I worked out that its the phono to phono leads that is picking the noise up from the pc to the amp.
I unplugged the leads from the pc and it still picked up noise, but when i unplugged the leads from the amp the noise stopped ? I tried better quality leads but it did not help would one of these help a noise ground loop filter ? as on ebay http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&Item=250392418513&Category=1498&_trkparms=algo%3DLVI%26its%3DI%26otn%3D1
thanks or any suggestions

[grahamdvddvddvd]

tried another power supply and the noise has gone completely ! the amp is 5amp can i get a dc power supply that big or would it be best to use a laptop brick style ?

[Luke122]

I doubt you would actually need a 5amp power supply for the amplifier.. that's the maximum draw that the amp will pull when running full volume. Try a 1-2amp to start, and if you have troubles, go larger.

[grahamdvddvddvd]

Hi thanks