I'm using the PWR-SPKR jack on the back of the 6400 to go into my mixer. What I've noticed with multiple 3.5mm stereo cables (TRS) is that when the plug is pushed all the way into the jack there is no audio. I have to pull the plug out just a bit to get the audio out of the jack. Seems like the contacts for the jack are not aligned properly. Has anyone else noticed this or is it just me?