HI at all. From various forums I've seen that one of the best headphones for mixing is Beyerdynamycs DT-880 PRO 600 ohm (now it's only 250 ohm, but someone tells about fastidious trebles using the new one and less general quality). Whatever I'll manage to find the old 600 ohm version, or another good pair of headphones with a similar impedance, I don't understand if I'll need an amp (and a good one) or if the phone output can handle it (quite levels for sure, but for mixing levels must be quite).
The manual don't specify this, and internet forums about this don't give a real answer. Someone says yes, someone says the max headphone impedance load is 300 ohm.
On this forum, one tread even seems to suggest this particular DT880. Comparing other brand interface's specs, It seems possible without an amp.
Can you please clarify the impedance range? And, even better, suggest the best suited phone load of fireface 400/800?
Do you think the  250 ohm version is good the same? The 80 ohm? Or can I drive a 300-400 ohm Sennheiser?
Thank you in advance for your kind response