QPad MK-85 audio jack interference

[snudge]

I've just received my brand new QPad MK-85 about half an hour ago, plugged it in, installed the software and it works fine (typing with it now). However, turning the backlighting on to any level gives me some horrid high-pitched buzz through my headphones (this is ofcourse using the jacks on the rear of the keyboard). I use TeamSpeak a lot and the voice test in the settings shows the buzz to be louder than my own voice.

I cant imagine this is normal?

 

[Tealc]

It seems that the audio voltages carried down the USB cable is being disrupted by the additional power the backlight uses, or maybe the backlight uses some sort of PWM circuit to drive the LEDs do you can adjust the brightness, which can often leak into the audio.

I can't imagine it's normal.

Easy fix would be to plug your headphones ini your sound device directly.

Edit: on reflection it's probably the PWM thing. What it does is switch the LEDs on and off faster than you can see. What you are hearing is this switching frequency in your audio.

 

[Sin_Chase]

Any extended audio port is going to be TERRIBLE for picking up noise.

Keyboard versions, front panels on cases - anything.

It is pretty normal and should be expected really. It's why I would never ever ever ever use Front Panel or Keyboard extensions.