Well we can hear the buzzing and wondered if you have a manual for this device thanks. I took it to a repairman once and he pointed out that all that had happened was a bit of dirtfluff had gotten into the post-return input effects he took it apart and said to his friend Wow look at this. Because you are inserting an EQ it does not apply the type of signal routing logic. My computer is updated and scanned for viruses daily I wouldnt have my perfect feedback if I spread the virus. We connect to related lists of other installation manuals manuals for other buildings mechanical systems such as water heaters watersoftens well water pump controls.Well we can hear humming and was wondering if you have a manual to this unit Thanks.I took it to a repairer once and he pointed out that all that had happened was a bit of dirtfluff had got in the effects send-return input He took it apart and was saying to his friend - wow look at this.Since you are inserting an eq that sort of signal routing logic just doesnt apply.My computer is updated and scanned for viruses daily I wouldnt have my perfect feedback if I was spreading viruses.We link to related lists of other installation operation manuals for other building mechanical systems such as water heaters water softenes well water pumps controls.