Thank you, I will say I did try the NiBL with it and no hum outside of standard tube noise. Surprisingly no hum from my El DAC that is currently feeding the BHC with no hum.
I also think the tubes that come with the mkii are noisy.
I’ll try all your suggestions, and report back my findings.
I’m having fun chasing this down! Also I didn’t try the NiBL with only my phone or iPad.
Thank you again for your advice!
Edit: ok dead silent with just the ipad and a 3.5-RCA adapter, I must have a ground-loop coming from one of the other devices connected to the Mac. I’ll process of elimination it, minus keyboard and monitor.
EDIT2: found! it was my keyboard! specifically when I have my LEDs on it going it causes the feedback! lol. Well that was fun I’ll have to swap out keyboards and see if it is that specific board or not. Now I can sit and enjoy my new amp! Honestly I can’t stop gazing into ol’Cyclops and its 5 irises lol. Also this thing ways a crap ton! I’m a big dude and I was shocked at how heavy this is for its size, pretty sure it weighs more than my 2year old daughter.