Hello everybody. I have been lurking for a long time on this site and this is my first post. No I didn't join just to ask for help, but I could sure use it. I have a PPI PC4800 that doesn't seem to turn on by itself. If I turn the car on, I get a strange pulsing sound and an eerie noise that sounds like a mumbling voice. If I unplug one of the RCAs and plug it back in, the amp kicks on. It will turn on every time I unplug and replug the RCA. It is a new install so I am open to the fact that it may be user error. I am feeding the amp a variable balanced signal from a stock head unit. I don't know if this is the problem as I think the ground is floating. The rear channels are bridged, and the front is set to high pass at around 70. When I first connected the amp one side would turn on but the other side wouldn't. When I unplugged and replugged the RCA the other side came on. I tried a Y cable to plug into both the front and rear inputs, but then both sides would not kick on until I unplug and replug an RCA into an input. I would appreciate any insight anyone can give me.