Technics SL-1200 Turntable "pioneer receiver feedback" Questions

...Pioneer DJM-350, but when everything is set up and I'm playing a vinyl, the sound is very deep and unclear, and also gets very distorted if I'm playing on high volume. I tried to connect the decks ...

...pioneer SX-3700 amp/receiver. The connection of the grounding wire to the amp reduces the noise approx only 20%. Noise is such, the music from the LP is barely discernable. Any thoughts on a cure? ...