More confusion reigns...
My day to day laptop died last Thurs, so I took home a "loan" laptop from work on Friday.
Both are Dells, but the loan unit is a bigger/heavier piece of kit. Both use the same PSU.

Rather bizarely, it sounds worse than the other Dell laptop when connected by HDMI into my HD621. I have absolutely no idea why that would be...

861v4/ID40/LPS, HD621, Roon, BAT VK-600se, Impulse Ta'us. Director/Heed Canamp with HD600s.