Seeing as I've had a little time on my hands this last week, I've been fidgeting with the USB HP interface a little. I also see skinny messing around with off the shelf stuff, so there must be a need for something like this. Before I commit more time to this, I was wondering what attributes people would like out of something like this?
1) Make it fully run off USB driving the headphones as well. This is doable, but for decent performance you need split rail supplies off the USB bus (I'm researching this a little still elsewhere) and you wont have too much output. Doing it this way forces a lot of compromises, but I imagine this being the most popular solution. To make this feasable, everything will have to be SMD, so will not be easy for the casual soldering novice.
2) If not the above, would it still be useful if it had to run from mains (or batteries for that matter)? This could be made with through lead components (mostly) that'll be a little more accessible to beginners.
I was thinking a two pronged approach: Firstly, do the USB part on one board and then make a separate board for the HP amp and switchers. This can be changed if you want line out or want to run it off mains.
When I get back I'll hopefully have time to investigate this a little further, but some ideas from your side might steer this in the right direction.
Cheers
Gert
