I guess I need to look into what the differences are between the 7 and 13 slot chassis.
Using my trusty calculator, the difference is 6!
I'm ALL audio at this point so I pretty much NEED a loaded chassis for any serious mixing! I'm using the Digi- branded SBS with the built in controller card and it's been working great.
I'm using a G4 and some of the earlier Chassis won't work with the G4, however that shouldn't be a concern with a 9600.
The earlier SBS and Magma need a 'interface'/'controller' card for the chassis itself... so for a 7 slot chassis, for instance, there will be 8 slots... one of which is for the chassis interface card and the remaining 7 for PCI cards. Most of the chassis I see for sale have this card already installed... as being installed in the chassis itself makes them harder to lose/ misplace.
Usually missing is the 'Host' card that plugs int the computer... these can be found on eBay ... The 13 slot Host cards seem to be more plentiful at this point in time for some reason.
The INTERFACE CABLE... Now THESE you don't find by themselves often as I don't think most resellers have any idea what they are for! The cable for the earlier chassis' is like a big fat ribbon cable with a protective outer sleeve (usually gray) that looks like some sort of SCSI cable. The connectors on the SBS and Magma are different from each other and NOT interchangeable so you need to find one for your specific brand. On these earlier chassis' I SUSPECT that the 7 and 13 slot chassis use the same cable but don't know this as fact. Also the cable length is important, as longer cables (beyond 4-5-ish ft??) will cause problems and may not work properly.
SOOOO.... I LOVE having the expansion chassis and for someone like me who is using mainly audio, I feel like its almost a necessity for any modern style mixing on a PT5/OS9 system. It's probably not as important for mostly midi or tracking smaller projects or for editing.
If I was just getting into the chassis game I'd hunt for one that was complete with cable and cards!
Jump in there Syntho... Chassis' for everyone!!!