REL T5i Subwoofer Hum issue

I followed all of REL’s suggestions on how to deal with hum but none address my issue. I’m using mine for stereo with my tube amplifier. All of the information I see or read just pertains to the left channel negative wire etc but the hum on mine appears to be coming from the red right positive channel. When I disconnect the right positive wire the hum stops dramatically and when I move the wire further away about seven inches or so, the hum stops altogether. I do have lots of wires and such around the area of the amp. Any ideas? I’m still waiting for a response from REL since it’s the weekend. 
Thanks
D