Hello I need help with connecting my 990 pre/pro to my 7700 amp. I dont really need balanced connections because I'm having all of my a/v components in one tall a/v rack. So how do I connect my pre/pro to my amp?

If you're not using balanced cables, you will want to use standard audio cables from the 990's pre-amp outputs (located directly to the right of the balanced outputs and above the 7.1 analog input) to the 7700's unbalanced inputs (remembering of course to make sure each channel of the 7700 is switched to "unbalanced" so it knows where to look for the signal).

well lemme ask you this, are the balanced cables better as far as sound quality goes? Or if I get unbalanced cables would it make a difference?

FYI, this topic has been covered in depth on this and other sites. Searching this site will give you a flavor of the various opinions. My take is that there are folks in both camps on whether balanced cables are really necessary to cancel noise induced in cables between a pre/pro and a the amp versus unbalanced cables. This is particularly true for the typical short cable runs in most HT racks. I bought only one set of cables so I chose Outlaw's balanced cables because I like the locking action of the XLR connector. If the balanced cables resolve a noise issue that exists in my home all the better for the money. Regardless, use high quality cables (e.g. Outlaw's PCA or XLR) between the 990 and the 7700 and begin to enjoy your new gear!

As AvFan points out, it's very difficult to get a single, consistent, definitive answer to your question. For longer runs, balanced can make some sense (although I've seen arguments against balanced even then - soundhound made some very detailed arguments along these lines last year). For shorter runs, it becomes more unclear. The XLR connectors do provide a secure locking connection, but you can also get locking RCA's with cables like Outlaw's PCA (one of the least expensive cables I've seen with locking RCA's). Definitely get good cables (I'd recommend either the PCA's or something like Blue Jeans Cables - both are reasonably price and well made), but I have not been able to convince myself to recommend that folks absolutely go one way or another (balanced or unbalanced) for the short runs we see when amp and processor are in the same rack. For that, the best I can do is suggest reading some of the discussions here and elsewhere and deciding what you and your budget are comfortable with.

While I don't have my 990 YET.......I felt the need to put my 2 cents in here.
I've been an AV hobbiest since 195X....

I also worked in the technical end of Hollywierd for some time.
I've never been able to hear a difference between the two types of cables.
My one main objection to the XLR connectors is the distance they protrude from the unit.
I have some Mac Intosh equipment that has them and I've never taken advantage of them on a permanent basis.

they also make XLR cables that are angled ... so they don't protrude out so far.