I agree with the Hosa's. I used the original ODL276, and I have the 276a, and the 312, and they work great.
I have one of the cheap "Gray box" ones I use on my living room stereo... allows me to feed my R4/laptop coax into the receiver's optical in. It works, but it just feels like a cheap piece of plastic that would fail when you need it most. I wouldn't use it as part of my main taping rig.
I've always run my Hosa's off a DVD battery, it draws next to nothing.