High pitched siren noise that does not change with volume when speakers are connected to Pre-Amplifier

[jg4rden]

My dad has connected his Jensen speakers to a Pyle PT270AIU pre amplifier system, but when the machine is turned on, a high pitched siren noise is produced from the speakers which doesn't change no matter how low or high the volume is set. The noise occurs even when I switch through inputs. Is a problem with the amplifier system or the speakers? The PT270AIU was recently purchased, but we've had our Jensen speakers for many years. By the way, I am not really audio tech savvy. I've been reading through threads that seem to have similar problem, but I have no idea how to start troubleshooting. Maybe I just need to exchange it for another system? Thanks!

 

[americanaudiophile]

It is impossible for a speaker to create a noise when the volume is all the way down. If the speaker had a problem you would hear the noise only when it was being played. To make sure that the problem is in the Pyle receiver disconnect any sources from it. Turn off any lights that can be dimmed too. If the Pyle has a 3 prong AC cord use a 3-2 adapter so that the ground pin is not in the wall. A ground loop can make this kind of noise and that is what you are eliminating with the above steps. If you still hear that noise then the Pyle is the problem.
If the noise isn't there with all sources disconnected reconnect them one at a time and see which one causes the noise. Cable boxes can cause this kind of noise due to bad grounding in the cable itself.

 

[drewdave124]

That is not true, actually my speakers create a louder EMI related (I think) noise when the volume is lower, i.e. the higher I turn up the volume, the lower the noise becomes, regardless of whether it has an input plugged in.