Hmm.. I was wondering...   My headphones are the famous K141 Monitor (600 ohm impedance) from circa 1990. On my pc they are perfect at 100% volume and flat EQ on my Soundblaster X-Fi. If I even rise anything in EQ I can hear some distortion.   Now, my question is: if any of you used...

Yep. They have 600ohm impedance. I have them from 20+ years and they still work flawlessly.   I wonder if AKG themselves made a new model sounding like these (the MONITOR ones I mean).   The K121 looks similar, and the K141 Mk II looks as an evolution.   But no headphones are 600ohms...