i use my q9h as a mp3 player for my truck. i have a oem micro usb to 3.5mm adapter. I have it running through a 300 watt amp and a equalizer. I just looked at my equalizer and saw that it it outputting a VERY high pitch noise whenever a song is playing. Also when i listen to metal, whenever it sounds like the sound goes in waves or pulses. I plugged in a iphone and it sounded perfect so it is not my truck. Is this a known problem for this phone or does anybody else experience this?