Issues with DMM

[Encounter]

Question. I have an older deluxe memory man and I get epic pops and buzzing in the mains whenever I engage it, followed by a delay of pops. Also a strange "rotary" sound. Although when I use it at home with my amp at a lower volume, it doesn't happen. Any ideas? Perhaps the cable I use at the church from amp to board?

[BoiceBox]

Do you run something different IN FRONT of the DMM at church as opposed to at home? How do you power it in each location?

[Encounter]

Everything is the same. Only difference is I use a shorter cable from amp to board at home, and a small power strip at church ;)