Posted by Bob on January 09, 2002 at 23:53:08:
In Reply to: QS6.1 Ground Hum Noise posted by Steve347 on January 02, 2002 at 20:46:42:
: I have a QS6.1 with a bad noise/ground hum problem. Here's the situation:
: With the keyboard unplugged from the wall, and audio lines hooked into the mixer, there is no hum of any kind picked up. As soon as I plug the keyboard into the wall, however, there is a loud static-type sound, not exactly ground hum - it's on the same frequency, only louder and more shrill. This sound is heard even with the keyboard TURNED OFF!! When I turn the keyboard on, a regular 60-cycle ground hum is added to the static distortion.
: This interference is loud enough to cause distortion when I record from the keyboard. Since the hum is there even with the keyboard turned off, I'm assuming its an internal hardware problem, which could be a costly repair.
: Does anyone have experience with this? And if so, do you know of a way to repair this or lessen it somehow?
: Thanks in advance!
: Stephan
Stephan,
Try using a ground lift adapter. Available at most Radio Shacks and hardware stores, and costs only a few bucks. There is nothing wrong with your keyboard; this is a classic example of a "ground loop", where there are two (or more) paths to ground - your keyboard and your mixer.
If your mixer uses balanced inputs (normally 3-pin XLR connectors) you can invest in a direct box with a ground lift switch (available at most music stores), this would not only correct your "hum" problem at home, but also anywhere else you might be taking your keyboard to, ie; gigs, studio, ect.
Feel free to email me if you have any more questions.
Bob