[billybob_jcv]

http://audioenginefiles.com/pdfs/D1%20review%20pdfs/Playback_D1%20review.pdf 

It says: Built-in high-performance headphone amplifier (20 ohm to 300 ohm optimal headphone impedance). So the answer is yes.

And good luck with three headphones. xD

By the way the HI2050 aren't a bassy headphones. They have a good low end but overall they´re neutral.

Having an amp spec that says use 20 to 300 ohm headphones tells you nothing about it's ability to adequately power the headphones. The HE-6 is only 50 ohms, but it also has an efficiency of only 83.5 dB/mW. The HE-6 would bring that amp (as it does most amps) to it's knees. When the amp mfr only lists the impedance range of the compatible headphones, they are really saying that the output impedance of the amp will support that range. They aren't promising you that you will be satisfied with the volume you can achieve.

 

[HyeVltg3]

Well now its just a waiting game, crap timing though, with Christmas around the corner shipping is going to take ages. Just order an unrelated to this topic item from Michigan and the seller was told by the post office that it may take between 3-4 weeks to get here (I live about a 2.5 day drive from Michigan, US ).
 
I ordered the 668D and HD330 locally(well 1 state over) so I expect to get them some time  this week or early next week. but the Takstars are coming from China (or Japan) wont be here till mid-Jan haha.

 

[dreamwhisper]

   
Buy some used HD558s off eBay

 

[HyeVltg3]

Well now its more about why would I get basic Senns if I could try out new headphones?
 
Just a quick Q: 
Do the Beyer DT990 velour pads would fit the HD330?
In my region, that would cost me a $48+S&H--mistake if they dont fit.