It is not much of an issue because I can get plenty volume even on low-gain but since it doesn't happen with the Magni 2 under identical conditions, I just wanted to make sure there was no quick/easy fix. RickB's suggestion sounds like it would be the best bet.
Thanks for the responses everyone.
I know a bit late in this topic, but I had the same crackling / humming issues before. I found out that if our electricity load is very high especially in summer (e.g. lot's of electric fans that is plugged in close to where you plug the amp), this issue gets louder. Try to plug the Asgard to an area with low electricity load and away from microwaves, electric fans or any electricity to mechanical device (i.e. vacuums, etc.) this noise will disappear like you've never heard it before.