[Cacka Lacka]

A few years ago I got the opportunity to listen to a friends DT770 Pro 80 on his amp (not sure what) and loved them.  At the time I owned a pair of Audio Technica ATH-PRO700 cans and some Monster Turbines IEMs (gray ones).  The PRO700s and Turbines simply satisfied my lust for bass, but the DT770s did this while also making the rest of the response so much more enjoyable.  Well, the bug bit me again recently and I purchased some 2005 Edition DT770 32ohm cans.  My first impression out of the box was that these DT770s weren't what I remembered from a few years ago.  They seemed to be disappointing down low and were shrill up top.  Thinking that they simply needed to be burned in, I've had them plugged into my old Denon AVR-3803 receiver for the last 48 hours, and after a second listen, there has been a noticeable improvement.  However, they still aren't as "awesome" as I so fondly remember.  The bass is definitely cleaner than the PRO700s and Turbines, but lacks the same punch that I love.  I'm thinking that over the last few years, my ears have become so used to the relatively muddy/distorted bass of the PRO700 and Turbines, that everything else just sounds anemic down low.  I'm still burning in the DT770s and will see how they sound after a couple more days on the Denon.
 
So now for my questions:
 

1. I've read that the DT770s (regardless of impedance) show a significant improvement when pushed with an amp.  Can anybody concur with this?  I'm currently running my phones without a dedicated amp or DAC.  However, I've been looking at getting the Fiio E7 and possibly adding an E9 if/when I decide to move up to the next rung on the headphone ladder. 
2. I was under the impression that the 2005 edition and pre-2005 edition DT770s shared the same drivers and had near similar sounds characteristics.  Is this true?  If not, is the older design of my buddy's DT770 Pros better in the eyes (errr...ears) of a bass head like me?
3. Do the DT770s require an extended amount of burn in? I don't recall my others phones taking this much time to settle into their natural sound.

 
 
Sorry for the long-ish post.  This headphone bug has bit again, and bit hard.
 
Anybody care to share some wisdom?
 
Thanks!

 

[Scytus]

I've never heard any DT770's, but I've read the pre-2005 pro 80's were the bassiest version of the DT770's there were.
 
I found this thread that might be helpful for you:
http://www.head-fi.org/forum/thread/346155/beyerdynamic-dt-770-80-pro-vs-dt-770-2005-consumer-edition

 

[Mad Lust Envy]

OP, the Pro 80s were what you liked. The Premiums don't have that massive bass.

 

[Riku540]

^ This. The Pro 80 Ohm vs. the Premium/Consumer 32/250/600 Ohm versions are completely different. The Pro 80 Ohm version is known to be a bass cannon while the Premiums are bass neutral.

 

[Cacka Lacka]

Thanks for the replies!
 
I guess I should have done some more diligent research before assuming that the PRO and Consumer editions were the same (sans aesthetics).  That makes me feel better that the "bass monster" DT770 I've been dreaming of actually exists and that I'm not going crazy.  I'm going to try and locate some PRO 80s and keep my Consumer editions so that I can hear first hand the differences between the two. 
 
One thing that bugs me about the pre-2005 edition DT770s is how unpleasing they are to the eye.  I know, looks shouldn't be that big of a factor in a  headphone, but the older style DT770 looks hideously dated IMO.  Are the drivers directly swappable between the pre-2005 and 2005 editions?  I'm guessing regardless if they are swappable or not, it's the acoustic characteristics of the cans themselves that lend to some of the sound differences?

 

[Scytus]

The DT770 Pro 80's do reportedly have remarkable bass, but only in the lower/sub-bass end. Many claim that it lacks the mid/high bass range punch.