[Pyrus]

So I recently ordered a pair of DT990/600 ohm headphones, and was wondering what amp/dac to power it with. I have a gaming computer with a Gigabyte z97 Gaming-5 motherboard inside that can supposedly power a 600 ohm headphone. With that in mind, if I were to purchase an external amp to pair with the internal amp, would that distort the sound in any way? My budget is about $300. If I could get any insight or recommendations, that would be much appreciated. Thanks in advance!

 

[PurpleAngel]

Guess you should at least try the DT990 600-Ohm headphones plugged directly into the motherboard. just to see what happens.
 
You could get an external DAC and headphone amplifier, the external DAC's line-output should feed a better analog audio signal, to an external headphone amplifier (then the motherboard jack).
A USB DAC would bypass the sound card features, an optical DAC would work with the sound card features.
 
You could get something like an Asus Xonar DX sound card, which has a nice CS4398 DAC chip (used on eBay, $60?), it does not really have a true built in headphone amplifier, more like a line-output that pretends to also be a headphone jack.
and plug any headphone amplifier you like into the Xonar DX.
 
I use an Audio-GD NFB-15 to drive my DT990 600-Ohm headphones.
$270 + shipping ($45).

 

[Pyrus]

I have a friend who swears by the O2/ODAC combo and is recommending me to get it. On the flipside, I've read that OTL amps are better for higher impedance headphones, while also taking the edge off the "harsh" highs of the 990's in particular. Any knowledge of this?

 

[cel4145]

I agree. The Audio-GD NFB-15 would easily drive your headphones. Good choice for the money

 

[PurpleAngel]

  I have a friend who swears by the O2/ODAC combo and is recommending me to get it. On the flipside, I've read that OTL amps are better for higher impedance headphones, while also taking the edge off the "harsh" highs of the 990's in particular. Any knowledge of this?

 
Listening to Bad Blood with my DT990 600-Ohm, plugged into my solid state amp (NFB-15.32), I'm not finding the highs harsh.
But if you want to try a tube amplifier, go for it.

 

[Itbesandrodoe1]

i have the 600 ohm model and use a magni 2 uber and a modi 2 and it makes them LOUD! so that would be a good choice!

 

[greenpsycho]

  i have the 600 ohm model and use a magni 2 uber and a modi 2 and it makes them LOUD! so that would be a good choice!

Same setup, but disagree: pretty harsh highs with the dt 990 and the modi/magni stack. Its totally a personal experience though, so you may want to try out something (or find a place with a good return policy).
 
I ended up switching my ifi stack and paired it with my 990's, which I'm liking much better thus far

 

[Shaffer]

I own DT990. You're on the right track. I'd suggest a Matrix M-Stage from the classifieds. It's way below your budget and will bring the cans to life. Forget about harsh highs. Good luck.