Hard drive and power supply adaptor creates speaker hum

[mat.w.]

Hi
I have ripped my CD collection to an external hard drive and play using Musichi software on a netbook and Cambridge DAC via a Quad amp to Quad ELS speakers. Not the easiest to set up but done now. However I am suddenly getting speaker hum when switching the power supply adaptor on and even more with the hard drive on. Its a new problem, all worked well at first. #

I have isolated each and every component and its those two items that are the issue. I assume its some form of feedback. I have swapped power adaptors and hard drives but the problem still returns.

Any solutions or explanation?

 

[John Duncan]

This is quite common - how is the netbook connected to the DAC? And is it the external hard drive power supply or the netbook's itself which is causing the problem?

 

[iMark]

Do you have a tuner connected to your amp? You may have groundloop hum.

If you have a tuner connected, try detaching the aerial lead. If the aerial causes the hum, you could try a ground loop insulator.

Do you get hum if the power supply on the netbook is detached?

In a previous setup I had a terrible hum when my stereo receiver was connected to the cable radio socket an my computer was also connected to the receiver. I solved this by putting a filter cable on the aerial cable.

 

[scene]

You could try some clip on ferrite cores around the power cables (if they haven't got them already) - this may help.