Weird sound coming out from my speakers.

[motbuddy]

hi,

I just bought a DIY kit which is a pre Amp+ 3 way control and a power amplifier kit. After i solder in all the components and screw the kit in a metal casing.I connect the audio input to a dvd player and i play a cd. It works.But there is a weird sound coming out from the speakers. It sounds something like " derrrrrrrrrrrrrr" which is quite loud if i stop the song or playing the song.

I suspect it related to the GND of the whole kit. When i clip the black color clip of my oscilloscope probe to the GND of the circuit i can heard a "piak" sound coming out from the speaker and the weird sound will be eliminated. Is it the GND of my circuit not strong enough?

i record the weird sound and uploaded to the link below.

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hope someone can help me on this.thank you.

 

[jaycee]

Does sound like a grounding problem. That is the same sound you hear if you have an unconnected cable to the input of any amp, and touch the middle pin.

 

[gootee]

http://www.diyaudio.com/forums/diya...udio-component-grounding-interconnection.html

 

[motbuddy]

how can i do if the player GND is not compatible with my circuit's GND? because when i off the dvd player's power but still in connecting position the weird sound will gone.

thank you.

 

[motbuddy]

Does sound like a grounding problem. That is the same sound you hear if you have an unconnected cable to the input of any amp, and touch the middle pin.

hi jay,

what u mean by the middle pin?

thank you.