Valhalla 2 :
Peak DC Voltage when turning
on: -0.103v ~ 2.799v
off: -2.246v ~ 0.971v
That's a figure I got from a person on YouTube , unless you want to massage your headphone diaphragms I would suggest un-plugging your headphones before turning it off , its like going for a back massage and then coming out with a broken spine
Again , I'm not bashing it , I own and love it but just keeping you guys updated for the safety of your headphones , take it or leave it ....
Not a big deal for me since my 150s suffer , not all
If I see numbers like that I suspect the guy has a ground issue in his measurement set-up. Maybe he should download the internet and search for "ground loop" and "common-mode".