I'm getting a slight buzzing sound coming from the left ear speaker of my L-700. I got them hooked up to a Woo-Wee which is connected to a Teac-Ai-100. The buzzing stops when I touch any metal object so I'm assuming it's a grounding issue. I tried using a HUM-X on the woo wee and teac and nothing changed. Any ideas on how to fix it? Or are my Earspeakers defective?