REL Sub Hum


Hi Folks, looking to see what the issue could be. I'm hearing a substantially loud hum coming from the REL T5/I sub when connected to the Parasound A23 power amp. The other two amps have no issues... what is a power amp would cause this issue? 

REL subwoofer is connecting using speakon cable... I have not tried LFE/.1 to see if the issue persists.... 

mullster