I have a pair of ATH M50's and I wanted to upgraded to Beyerdynamic DT 770 PRO. Does anyone know if these headphones in this video are the 80 ohm version or the 250?
 
http://www.youtube.com/watch?v=V0QBqJaN2qg at 4 min 30 secs.

Can't tell. I have the 250's which sound awesome but are in need of an amp of which I will purchase soon. The 80's are less likely to need am page depending on your source.

Sent from my SM-N9005

So the only difference between the 80 and 250 ohms is bass?

I too own the 250s and think the sound is quite nice. Everything I've seen says the 32 ohm ones sound about the same, and the FR charts seem to support that with the curves being REAL close. to each other. Beyerdynamics say that the only real difference between the various DT770s is the Pros have more clamping force than the premiums. 
 
OTOH, given the great price amazon has on the DT770 pro 250 ohms ($150 or so) you can buy them and a nice DAC/Amp for about the same price as the 32ohm version. And I'd much rather have a DAC/Amp than not. I have the NuForce uDAC3 and it drives them pretty well. The FiiO DAC/Amps get good reviews as well. Generally the FiiOs are more flashy, the NuForce more built like a tank. Both have similarly decent quality for ~$120 or so DAC/Amps. I prefer to EQ in the digital domain on my laptop so I don't need 32 ohms for on the go nor do I need EQ in my DAC/Amp. YMMV.

retskrad said:

  I have a pair of ATH M50's and I wanted to upgraded to Beyerdynamic DT 770 PRO. Does anyone know if these headphones in this video are the 80 ohm version or the 250?
 
http://www.youtube.com/watch?v=V0QBqJaN2qg at 4 min 30 secs.

Click to expand...

The couple sitting together are using the DT770 Pro 250-Ohm headphones, both headphones have coiled cables.
The guy sitting by himself is wearing the DT770 Pro 80-Ohm headphones, straight cable.
 
If you want to upgrade from the ATH-M50s, get the Audio Technica ATH-A900X closed headphones, plus Hifiman Velour ear pads.