Which amp/dac for Ultrasone HFI 780 (around 250).

I have a question regarding amps and I wasn't sure where to post it, as I am not sure if I want a portable amp or a desktop amp.

I have recently purchased a pair of Ultrasone HFI-780 headphones for use at my home desk and would like a way to conveniently switch between sources, I would also like a DAC. I am currently looking for an option that accepts usb (as a dac) a LOD from my ipod (less important on a non-portable) and optical from my xbox360. I listen primarily to hip-hop (a tribe called quest, del tha funkee homosapien).

I currently have an old airhead portable amp; however, I do not like to sound from my laptop into my JVC marshmellows (from other sources, it is better), so I would like a DAC. I also do not enjoy manually switching the plug between various sources and would like to leave the headphones plugged in as much as possible.

I have been looking at two amps that I would purchase used from the forum - the ibasso d10 cobra (portable) and the audio-gd compass (desktop). If I purchased the Cobra, I could sell my airhead - this is a benefit. Which of these amps sounds better with the ultrasones? Is the amp in the d10 a large improvement over the airhead with a can that is relatively easy to drive (like the 780s)? Will either amp somehow work better with gaming (not that big of a concern)?

I am currently leaning towards the d10 because I would be able to sell my airhead. However, I may do this anyways if the ultrasone sound decent unamped. (I dont know how often I will be using them away from my desk anyways)

An update: What about the Zero DAC/AMP that can be had off of ebay?

Is it possible with this model to use just the amp through the opitcal in? I would like to use it as a DAC/AMP from my computer and just an AMP from my xbox360.

Hey guys,

I have continued to look around and have been considering a Zero from ebay. I have heard there were issues with build quality and that SQ can very greatly from amp to amp. Is there anyway to know before hand?

I have come to this decesion based on the fact that I do not really need a fancy portable amp. I currently have an airhead and will probably pick up a cmoy bass boost with LOD for my nano. However, if the D10 sounds significantly better than the zero I may be swayed in that direction - the d10 appears on the for sale forum enough. My first choice, the audio-gd compass does not seem to be for sale that often and is out of my price range new as this is just a desktop starter system. I am also in Canada, which complicates things slightly.