sure, shoot me an email and I'll send the sch and brd in a zip (my addy is at the bottom of every post)... I've got a bit newer version than what's pictured... I optimised it a bit more based on my fab house DRC specs, and added ESD protection diodes to the inputs.
I'm still confused about the op-amps idea (and a little concerned regarding my design).
I get the need for an amplifier if headphones are used, since they're not a high impedance input like a line input would be on a set of powered speakers or a stereo receiver. Is this the root of your op-amp based design, sort of a pre-amp for headphones?
My design is going to be feeding high impedance line-level inputs only, no headphones or un-powered speakers... the input sources will all be line-level outputs from sound cards and perhaps a line-level feed from my cable box.
bmw, another thing I found while working on this project, if you use linux and alsa, you can split up a multichannel sound card into three (or more) discrete sound cards... really a expense saver and space saver ... with two SB Live! 5.1 (old ones) cards I have eight outputs on my media server, as each card offers three stereo outputs, plus the two stereo channels from the onboard sound. Plus I still have two pci slots free for additional cards ... the new SB Live with 7.1 has four stereo outputs, but I haven't seem the price drop on them yet.
You have to watch your cpu usage, too many heavy duty apps and the audio can hickup, but I've had six streams of shoutcast running using mpg321 with no problems at about 40% util on a celeron 933