The Building Blocks of a SAC System
A SAC system consists of a good Windows computer, a professional sound card, and AD/DA converters. The software is written in Windows assembly language so must be run on a computer incorporating the Windows operating system.
Most SAC users assemble their own system but there are companies that produce SAC systems complete. Advice is readily available on the SAC forum if you run into problems with your build or getting the system stablized. If you are into computers at all buying the parts and assembling the system should not be a problem. Computers are made up of building blocks and all you need is to be sure that the parts that you buy are compatible. Assembling the computer takes little technical knowledge. Generally the only tool required is a Phillips screwdriver.
The Host Computer
For use with SAC the computer should incorporate a fast dual core processor. Because of the nature of real-time audio the primary processing of audio data needs to be done on one core. The graphics data can be handled by the second core. Speed is the most important item along with stability of the system. I generally use Gigabyte motherboards and Intel processors in my in the computers I build but that is just a personal preference.
The Sound Card
The professional soundcard is likely to be the most expensive single component in a SAC rig if purchased new. Soundcards by RME and MOTU have proven to be reliable in SAC rigs. I use an RME RayDat card in both of my SAC rigs. The RayDat card incorporates 32 channels of in/out via light pipe and stereo in/out via SPDIF and AES protocols for a total of 36 channels of in/out. The drivers can make or break a hardware device for use in a computer. The sound card needs good stable ASIO drivers to attain good low latency performance.
For inputs and outputs you need AD/DA converters. These convert signals from the analog to digital realm and back to analog when the processing is done.
There are a wide variety of options in converters. The most common converters used with SAC systems provide eight in and eight output channels on a single rack space chassis. Prices begin below $200 and range upward from that point.
SAC was designed with significant remote control capabilities. Nearly anything that can be done on the host computer can be done by remote control over a computer network. The software can handle up to 28 remote work stations. In order to use the remote capabilities you need to establish a network and have something in the way of a remote computer.
Networking can be done either over a wired network or via wifi. Wired networks are more reliable, but most often I mix FOH over a wifi connection. I have recently added powerline networking adapters and have used them in situations where I did not want to depend on a good wifi connection. If several remotes are to be used most of them should be through wired connections and a network switch.
Remote computers do not process any audio so the requirements for processing power are minimal. Lowly netbooks have performed well for me throughout my time as a SAC user. When setting up a fixed FOH mix location I usually plug in a monitor and keyboard. The extra screen real estate and the full keyboard functionality are worth the extra effort.
The basic requirement for a remote is that the computer uses a version of the Windows operating system. Some users have successfully used a Mac or Linux based computer using Windows emulation or dual boot. There is no iPad App for SAC, nor should one be expected, but full Windows based tablets are now available and can be used as remotes.
With my remote I use a wireless mouse. I would probably still use a wireless mouse instead of a pen if I were using a tablet. I also use a numeric keypad since the keyboard on the netbook does not suit me well.