Record DI through KPA & record a mic off a cab at same time???

Anyone know how I can record a DI through the KPA with direct out….that I can do, and record a miked cab… can do that too…. but for some reason I can seem to get both of them recorded at the same time without a hum/buzz/some other sound coming through the DI output. Re-amping and DI works great when I have the main out or speaker out disconnected. But when those are hooked up the hum is present. Any thoughts???

No but I will today. I doesn't appear to be a ground hum issue but I will try it and let you know.