The API Audio 7800 Master Module is a piece of gear to use in tandem with either the API 8200 or the 7600 modules. I've used it with a series of 8200 line mixers, as it's almost like having a console if you've got this and a few of the eight channel line mixers. The connections that the 7800 has include 1/4" jacks for monitors and other routing options, as well as D sub for auxiliary and bus outputs and an XLR input for a talkback mic. It is rack mountable and will just take up a single space.
The make up of the API Audio 7800 has a decent amount going on since they are trying to squeeze so much on a single space rack mountable unit. The 7800 includes sections for controlling your monitoring levels, talkback mic, send and bus masters, and solo control. It's basically got everything you'd expect to see in the main control section of a console. I haven't look at the manual, so I don't know what it looks like, although I would recommend having it handy just in case.
The API Audio 7800 won't affect your sound negatively, as it's got sturdy connections all around. It doesn't make any sound of it's own at all, as it's just a control station. It's the 8200 line mixers that will make the big sound difference that you're to use with the 7800, as it's not really meant to be used on it's own. API circuitry is some of the best available, so running everything through this is absolutely more than dependable.
If you're looking to get the feel and sound of a console without actually having one, the API Audio 7800 is a great place to start and to use with either the 7600 modules or the 7200 line mixers. This is a great way to get the console features and sound without spending too much money relatively where compared to a console. Another huge factor is that you can fit this and three 7800 line mixers (24 channels) all in a four space rack casing! This is a great option for smaller studios looking to get a big sound in small space...