Pro Tools 101_ An Introduction to Pro Tools 11 ( PDFDrive )

Pro Tools|HD Native hardware provides up to 64 channels of I/O, while Pro
Tools|HDX hardware provides up to 192 channels of I/O. Pro Tools|HDX
hardware systems are the most robust Pro Tools option available, utilizing
superior DSP hardware and technology to carry out real-time routing, mixing,
and processing of audio signals and support for up to 768 simultaneous
Audio tracks (record and playback) and up to 512 simultaneous MIDI tracks.
Pro Tools|HD Native and Pro Tools|HDX hardware systems require at least
one HD-series audio interface to be connected in order to run. All current
Pro Tools HD-series interfaces can be used for Pro Tools systems with Pro
Tools|HD Native, Pro Tools|HD Native Thunderbolt, and Pro Tools|HDX
hardware.
HD OMNI
HD OMNI provides two premium mic/DI inputs with built-in preamps, four
line inputs, and eight line outputs in a compact, single space rack-mountable
chassis. It also provides digital I/O, including eight channels of ADAT I/O
with S/MUX II and IV support, 2×8 channels of AES/EBU I/O, and two
channels of S/PDIF I/O.
Figure 1.21 Avid HD OMNI audio interface
Source: Avid ® .
HD I/O
HD I/O is available in one of three configurations, providing differing analog
and digital I/O options. The standard 8×8×8 configuration provides eight
analog inputs, eight analog outputs, and eight channels of AES/EBU digital
I/O, in addition to two channels of AES/EBU digital I/O provided on the
chassis in all configurations. The 16×16 analog configuration provides 16
channels of analog input along with 16 channels of analog output, plus the
two channels of AES/EBU digital I/O on the chassis. Similarly, the 16×16
digital configuration provides 16 channels of digital input and 16 channels of
digital output, plus the two channels of AES/EBU digital I/O on the chassis.
Figure 1.22 Avid HD I/O audio interface