nope, it is correct, based on my experience.
you can use an amp with uber wattage to an he6 or a k1000, but it will just sound "normal" unless you get high current running through the amp as well. the 6w (or was it 8w) lyr cant drive a k1000/he6 at all, based on my experience. it can play it at decent volume but with volume knob at 4-5 o'clock :P
also, most 15w 30w power amp can make the two headphone to loud volume, but it doesnt sound spectacular to me, compared to diy amps with big current with decent wattage.
there are a few exceptions though, and this will go on so ill just end it here
oh, if that's so, then I don't mind :)
I didn't know much and was guessing, but thanks a bunch Dyaems!