Help, my partner has very kindly given me a 3300 turntable but when I have tried to connect it to a modern Marantz amp, (KI signature) there is very low volume output and massive hum. Is this something to do with the earthing or do I need to buy a pre-amp? If I need to buy a pre-amp, what do I need to look out for or has anyone had any experience at all? 