picking USB DAC: does stacking a USB DAC/AMP with a desktop headphone AMP cause problems?

[opis]

So, previous setup I used the onboard mobo soundcard (which was.. alright) and just connected it to a JDLabs o2 amp to drive my headphones. I couldn't afford an alternative at the time and it did the job.

So now I got a new mobo, tl:dr; turns out on this one the gpu is real close to the onboard sound card which is not great (and has less output power than the prev one), I get coil whine from the gpu at high fps and basically I think I need to get an external USB DAC to bypass the whole problem, which is something always wanted anyways, and can now afford.

So I need to buy a USB DAC, preferably the "cheapest one that does the job" (say if we can stay around $100/£100 that'd be great), I'd like a clean DAC without an amp and then line it out into the o2 amp I have.. I know the Dragonfly ones get a good rep.. but I also notice a few decent looking DAC+AMP combos (like the Schiit KA1/2) that are a bit cheaper.. but then I wonder: is it a problem that the USB DAC has a built in amp if I intend to connect it to the o2 amp? I mean does combining two amps cause a problem?

I run HD600s with this which are fairly tough to drive (bulky magnets and 300 Ohms).. I like to listen to music on pretty loud volume at times, and I found that even with the o2 amp, older recordings at below 90 dB really require a lot of power to get to high volumes.. so not sure if the built-in amp on say a Schiit is enough by itself?

Any recommendations otherwise in the price range for a USB DAC without an amp that does the job and we can let the o2 do the amping?

thanks friends

 

[tjl5709]

You do not want to double amp your signal, it can add and amplify static/hum. If you have an amp currently, I would get the best DAC you can for your money. I've found you get allot of value from the Schiit stuff. Is the used market an option? Lots of folks have upgrade fever.

 

[opis]

Hey, thanks for your reply. Yeah that's what I suspected as well. I'm not sure there is a big used market around where I live so I've decided to just get something bang-for-the-buck-ish off of Amazon, but I hear you.

I'm leaning towards an iFi Zen Air DAC, connect it to the computer (USB-C to USB-b) and then use the line out from the DAC via 2RCA to the o2 amp instead. The reviews of the Zen Air DAC on here make it seem alright, but I am freestyling with no experience at this point any input on this idea before I pull the trigger? thanks