As Zombie stated on his first post, the DT880/32 sounds a lot like the DT880/600 but with less refinement. I myself owned the DT880/32 and thought they were amazing. Though they can be driven without an amp, they too benefit quite a bit from amping. Though with a decent source, they will be driven quite loudly.
I can confirm that. I have Mad Lust Envy's old DT880, and an amp will help quite a bit with dynamics, or else they do sound a bit lifeless.