Is dac variable output worse than fixed?

Got new headphones that need more power than my current setup. Was told to get a higher end schiit. The only issue is the l/r output from my dac is variable, and someone suggested that would be bad. The dac cost like 250 so i dont want to trash it if it's not going to actually negatively affect the audio. Could someone illuminate me on whether or not that will be the case if i run an ipod through a certified dac to a schiit via the l/r?

You need to give more info, dac model, current setup models, headphone model, which Schiit model ect.

For any constructive answers to be given, otherwise you'll just get a lot nothing posts.

Cheers George
The DAC is the Nuforce Icon Ido. It said its amp could power power hungry headphones so I assumed it'd be enough. The site with the manual is
Page 6 is the connection info; 7 is the technical info. 

The headphones that feel a little under powered are the hifi he500. 

For my other headphones, lossless audio through the IDO was quite enough.

The recommended step was for me to get the asgard2 for my budget, and output the ido via l/r to asgard. However, I found out the ido is variable output, and was told that couldn't work and to find another dac entirely along with the amp. Just trying to weigh my options. 

I'm not up on this stuff but from what I can see the Ido is a headphone amp 2v out with built in dac, if it's output is to low for the 38ohm 89db he500's, the get a $99 Schiit Magni 2 much more powerfull it's output impedance is .2ohm, Gain: 1.5 (3db) or 6 (15.6db), selectable via rear switch. And will give 1.2watts into the He500's 32ohm load. Leave the Ido up full.

Cheers George 
Thanks so much! Glad to hear that variable output won't be a death sentence. Will do.

Last question. Since you recommended it, what would I set the back settings to on the magni 2 for the he500? There are 2 switches and im assuming the I and O are off and on, but do I choose high or lo?
what would I set the back settings to on 
Gain: 1.5 (3db) or 6 (15.6db), selectable via rear switch.

Which ever one gives you the most usable range of volume with, min to max.

Cheers George
Ah, thank you! I was afraid hi might blow out headphones for some reason. 

Thanks again for all the help!