I'm guessing you didn't want to use coaxial-to-optical converters or didn't want to use optical from sources that offered both, right? (Edit: converter ...)

You are correct gonk. I'm not even sure I knew about coax to toslink converters at the time. And now that I know about them, lack of inputs isn't an issue.

Now all I'm lacking are HDMI inputs that accept multichannel lossless audio, but I think I can live without that for some time to come. Particularly since my future HD DVD transport of choice (Xbox 360 HD DVD drive) doesn't offer HDMI 1.3 output.

Although really, I'm waiting for Oppo to come out with an HD-DVD transport.

Ive tried both unbalanced and balanced outputs on the 990 and they both pop. my bryston 4B is balanced and the 2 3Bs are unbalanced.
I'm starting to think it might have something to do with the 990 not having a 3 prong plug on it and not having the same ground potential as the brystons.

Oh sorry, forgot to check the manual on the 4b.

went through many attempts at solving the problem...even called bryston.
I ended up buying a Denon 988 from a local store(with the intention of bringing it back within the 30 day period). there is absolutely no popping sound from the Denon(using the pre out from the denon connected to the brystons). I will return the Denon 988 and buy a Denon 3808CI once the Outlaw 990 is sold.
I find it a shame that the 990 didnt work with the Bryston because of the dc change at the ouput of the 990. Overall I find that the 990 was a great product and would have held on to it a while longer if not for the interaction with the bryston amps.
-thanks to everyone for the help.