HELIAS

I don't have a recommendation, nor am I interested in discussing "house sounds" of DAC/amps whose only job is to be noise free and...

No. Amir's chart is in dB. At 1V 50 ohm, the Kann is -100dB which is 0.001%. https://sengpielaudio.com/calculator-thd.htm Neither...

I can't comment on any device you mentioned. I don't own them. Kann Ultra's output at 50 ohm is not impressive but still should be...

That graph means it can't make low impedance low sensitivity headphones (planars typically) loud. The steep hill on the right is not...

I don't think I will be able to tell the difference in a blind test if I plug the same pair of headphones into the Kann Ultra vs Qudelix...