The problem
is common to all surround processors and receivers. In fact, the 990's delay is on the fast side compared to some. Products based on the older 49300 can take noticeably longer (Outlaw's old Model 950 took around 1.5 to 2 seconds, depending on the signal type, and Emotiva's LMC-1 takes 2 to 3 seconds). It's a pesky side effect of the broad array of possible digital signals available to us.
I'm thinking that there ought to be a CD-stereo mode that pre-sets the decoding to avoid the lag. I wonder if the concern was that for other source types such as movies, you could have a situation where there would be no sound at all in the CD-stereo-only mode?
The Model 950 did include something like this, as you could "lock" a given input on a certain surround mode. The 990 dropped this, as I believe did the 1070/970. This was likely due in part to the faster acquisition time, but part of it was also likely a reaction to fears about users getting messed up by it. Cable and satellite receivers both offer an assortment of possible signals (especially when you toss HD into the mix), DVD's can carry every possible format and routinely employ at least two different formats just to get the movie going (menus use Dolby 2.0 most of the time), game consoles and media players are just as bad as DVD's about being impossible to pin down, and even the trusty CD can potentially throw DTS at you as well as PCM stereo. I don't know what you would hear if you decoded DTS as PCM, but you would either get nothing at all or you'd get an incoherent noise that could potentially inflict damage on speakers if the volume was too high at the time.
One thing that does eliminate the problem is to use an analog connection for the CD player.
True - you
can avoid the problem by using an analog input, assuming that the CD player itself doesn't have any such delay. A CD player is likely designed solely to work with standard audio CD's, in which case it'll work fine with PCM stereo but probably can't play DTS CD's at all (no DTS decoder). A DVD player used for CD playback
may still have the problem, though, just at a different place in the signal path.