I have a 5.1 setup using the 990 7.1 audio outputs to listen to SACD/DVD-A. Now I'm considering going 7.1 but what happens to my SACD/DVD-A listening?

There are two possibilities. First, you listen to SACD's and DVD-A's in 5.1 and the rear surrounds stay silent. Second (this comes out of the HD-DVD and Blu-ray format war and the odd tendency for those players to not offer 7.1 analog outputs), you split your left and right surround outputs from your player and send the each signal (left or right) to both side and rear surround channels of the 990's 7.1 input. Personally, I am doing the former - my rear surrounds simply don't do anything while listening to DVD-A and SACD.

I guess this is a good time to ask... Gonk, I have tried both of the setups you mention here and, by far, splitting the rear channels (turning 5 into 7) sounds better to me.
At least on the SACDs that I listen to I have noticed less bass than on conventional CDs - I have Dire Straits Brothers in Arms in both formats and the Stereo-CD played at Stereo-7 on the 990 sounds almost as good as the SACD (I've had that CD for 20 years!). After spliting the rear channels for SACD 7.1 direct, the bass appears to have increased. Do you think this is an illusion? or is the 990 actually "summing" the bass from the extra channels even though it is the same information as the side surrounds? (they are all set to the same crossover, 80hz).

I'm Curious,
Are you splitting the surround channels between your dick plarer and the 990, or between the 990 and your amp?

With a CD in Stereo 7 mode, you will notice more bass than with an SACD or a CD in straight stereo mode (due to the nature of the way Stereo 7 duplicates the left and right signals and then sums the bass back). It (the extra bass) is a common remark by folks using Stereo 5 and Stereo 7.

One thing that I'd probably at least try when using the split surround trick is running some test tones through the DVD player to determine if you need to trim the surround outputs down any at the player. Splitting the signal will decrease the signal strength to each channel (side and rear), but I'm not sure that the decrease will match the corresponding increase produced by the signal being reproduced by both speakers (side and rear) - if you end up with a higher overall SPL, you'll also get a little more low frequency SPL. I wouldn't expect it to be significant, but there might be an extra dB or two hiding in there somewhere.

He's splitting the surround outputs between DVD player and 990 - the player's left surround output is split and sent to both left side surround and left back surround channels of the 7.1 Direct input, and the player's right surround output is split and send to both right side surround and right back surround channels of the 7.1 Direct input.

Thanks, at least I know I'm not imagining that part. I might not go as far as measuring SPL on the 7.1 mode unless I feel really bored one of these days. I like how it sounds now, so I don't want to kill the illusion (if that's what it is).

FYI...

Zektor is allegedly preparing to release a 7.1 analog audio switcher, any day now.

I'm stoked.

Ooops. Thought this thread was about switching 7.1 analog, didn't read carefully. I apologize for cluttering.

Hey, no apology - that's an interesting bit of news!