[markot86]

The dac I'm interested in has a coaxial input but I'd like to use the optical out from an airport express. Has anyone used one of these to convert the two? what were your results?

http://www.uniqueproductsonline.com/tooptococodi.html

I'm mainly concerned about what kind of an effect this will have on jitter/sound quality.

 

[IronLion]

I've never used one of those but personally, I'd stay away from them. I just wouldn't trust that that thing would do a good enough job converting the optical to coaxial without introducing more jitter. Personally, I'd look for another DAC, or another way to get a coaxial digital out off of your computer.