Ah yes.  He looked a little buff in that render, threw me.  Separated at birth?   

What are you talking about?  We are living in the last great mustache age.  You must never have been to the Mission district of SF?  Mexican families + 24 yr old white hipsters with mustaches?

This seems to be one of the better quick summaries of Tesla Beyers, followed by a pretty funny post by Kiteki, as he finds the one positive in the whole post and declares they must be amazing and will sell like hotcakes.  Pretty good example of the rosey colored hype machine. 

http://www.head-fi.org/t/607079/beyerdynamic-t90-d/180#post_8440072

just wanted to share my impressions of the T90 - compared to HD600, t5p, t70, t70p, dt1350, dt880 250ohm
 
yesterday i visited a hifi shop in berlin / germany
 
the salesman said that the t90 was running in for 2 days.  gear:  mf m1 hpa (ss amp) + consonance cd player
 
the t90 had the same issues as all other tesla series - bright, empty body, unmusical, awful tonality - maybe a tubeamp would help
 
the t5p had the best definiton, transients, separation and a really nice kickdrum and overall tonality of the beyers
the t70p was really bright and lacking in the bass
the t70 bright but a nice midbass
the t90 almost had the speed/resolution of the t5p but lacked in definition, imaging, bright tonality and the bass weakest of all beyers. (maybe more burn in?)
the dt1350 was fast but lacked in prat and couldnt reach the performance of the larger beyers - would easily prefer my slower M50.
the dt880 was slower, had less resolution but had the best body and prat of the beyers with good tonality (actually all the tesla cans lacked in coherence, timing and body - no prat at all with those amps)
 
my stock hd600 was slower than the tesla beyers but it had the best prat of all (only with the m1 hpa. the lehmann rhinelander and mf v-can couldnt deliver the pace and timing of the m1 hpa) + great tonality, coherence and warmth / body. it easily was the most enjoyable of all.
 
sorry all beyrer fans but the t90 had really low bass level and an uncomfortable peak in the highs with the usual tesla tonality.

"Thanks for the amazing review vonjuergen. So the T90 has the speed, resolution, depth, presence and realism of the T5p?  omggggg it's going to sell like hot cakes now.
No bass well equalizer+XB1000 = fixed"
 

On one hand it's considered bad form to make fun of the mentally ill.

On the other hand it's considered bad form to make remote diagnoses.  Especially when you're not even qualified to make local ones.

What to do, what to do...

Originally Posted by jcx

kind of like asking "I've got a high end carbon fiber bike I'd like to carry on vacation - should I buy a Monster Truck with the extra Chrome option??
 
the Dark Star uses bridged output high voltage power chip amps (==op amps, and poorly speced for audio compared to LM3886)
 
its sole objective justification is driving insanely low sensitivity, lower impedance headphones - HiFiMan HE-6, you also could justify using it for the high V swing with AKG pro "monitor" headphones intended to connect direct across a normal audio power amp outputs
 
 
the HD-800 and the Dark Star don't belong together - the HD-800 is a High Z, moderate sensitivity headphone at 300 Ohms, can be driven to >120 dB SPL with ~12 Vpk, 40 mA - no need for 60 V, 4A
 
the objective, manufacturer's datasheet performance graphs for the power op amps used in the Dark Star show evidence for rising distortion at low signal levels - almost certainly crossover distortion -  "lower levels" is the only place you would ever use on the Dark Star with the HD-800 - and crossover distoriton is generally considered the most audibly objectionalble"

And the manufacturer's response (laden with too many technical terms to decipher to explain his design choices):

The DarkStar & HD800 work very well together my friend. In fact the Dark Star brings the much needed warmth to those phones that tend to be on the bright side.
If you happened to be at the next up coming RMAF, please do stop by our table to give the DarkStar a listen with any hard to drive headphones or high impedance phones.

[I understand a user's line of "just try it" as there is no reason to expect them to justify a manufacturer's engineering choices.  But when said manufacturer chimes in and completely avoids the salient technical points, their credibility as an engineer just goes further down the tubes.]