Distortion on line-in when using A/C adaptor through IMac

[jprochceo]

Trying to stream my RS Pro 106 through my iMac. Going from headphone out of scanner to line in of iMac. Works fine when powered by batteries. When powered by A/C adaptor get severe background hum while streaming even when scanner is not on. Even get hum through computer speakers when not streaming. Adaptor is RS 9V, 800 ma, tip is positive.

No distortion when using A/C adaptor just listening to scanner when not connected to line in.

Any advice is appreciated.

Thanks

John

 

[colinpeddle]

I believe you need a Ground Loop Isolator. Radioshack sells them. http://images-cdn.maplin.co.uk/full/vw43.jpg Should look something like that, though the one I have has a RCA in and 3.5mm headphone jack out, which is more what you need. Ebay too of course.

 

[jprochceo]

Thank you for the information.