Both are quite good headphones, certainly at this price. Impedance differences are not that big. The 32 Ohm is about 1/10th of the 250 Ohm where the 250 is only about 1/2 that of the 600 Ohm. Measurements of various DT770's seem to show substantial tonal differences. Beyerdynamic also claims that there is no difference between the 32 ohm and 600 ohm version of the DT 990, which is wrong. The fact is, the DT 880 black, as you can see in the link I have provided, has substantially more bass than the Edition model. Dont trust marketing, no matter what they say. Beyerdynamic with their new DT 900 PRO X is among the first to offer open-backs suited for any workflow and has created perhaps the most versatile open headphones to date! Pros. Plenty of volume in any setup. Great build. Easily available spare parts. Pros list with SoundID Reference calibration. I like to recommend the monoprice liquid spark for a amp and use a dongle DAC like an apple USB C dongle but if your willing to stretch the budget you can easily buy a nice $!00 DAc to go with your amp. liek the JDS labs atom DAC or the Schiit modi or the rather unique earmen donald DAC. the reason I reccomend the liquid spark over any other Beyerdynamic dt 770 pro 32, 80, 250 ohm all versions need 100 mW power. In this case, how is it easier to drive 32 ohm headphones than 80 or 250? if the audio interface audio output has a constant voltage ; 32 ohm dt 770 pro, uses much more amperage ( 'i' ) than 80ohm or 250 ohm dt 770 pros While the DT 990 Pro is one of the lighter headphones in its class, the Beyerdynamic DT 900 Pro X weighs over 70 g more and tips the scales at 343 g without a cable. Therefore, it is good that the Pro 900 X is stronger in terms of contact pressure. Otherwise, the fit of these headphones would not be as secure as it proved to be in practice. The famous DT 990 Premium, 32 ohm version; Stereo Headphone for MP3, iPhone, iPod and home audio applications, analytical, true sound reproduction. Connectivity Technology: Wired. Made in Germany, innovative "Bass reflex" system for excellent audio performance. Open design, includes carry case, 11 oz light weight. Best amp/dac for dt 990 pro 250ohm for gaming. Amplifier - Desktop. so i currently own dt990 250ohm and im looking for amp/dac for 100Euro or less. im using them currently for gaming. im currently looking at fiio k3 and E10k but dont know a lot about audio so thats why im asking it here. thx for your time. Heya, 600 ohm Beyers run fine off most things too. Beyers are very efficient, despite their impedance ratings. It's due to sensitivity. But a lot of questionable information floats around about the different impedance versions of the same headphone regarding Beyer. And not every portable player and laptop has the same level of current They differ substantially. There are even audible differences between various DT990's and DT770's. People have a tendency to overestimate their hearing capabilities. Use your ears to listen to music not as an analyzer. DHyF.