Specifications

Chapter 1: Introduction 1
chapter 1
Introduction
HD I/O is a multi-channel digital audio interface
designed for use with Pro Tools|HD
®
systems.
HD I/O features 24-bit analog-to-digital (A/D)
and digital-to-analog (D/A) converters, and sup-
ports sample rates of up to 192 kHz.
HD I/O comes in three standard configurations:
• 8 x 8 x 8 (8 analog in, 8 analog out, and 8
digital in and out)
• 16 x 16 analog in and out
• 16 x 16 digital in and out
You can also add or remove analog (ADC and
DAC) and digital cards for custom configura-
tions.
HD I/O Features
HD I/O provides up to sixteen discrete channels
of Pro Tools input and output, each with a 4-seg-
ment LED meter. The total available analog and
digital I/O is dependent on the configuration of
Analog and Digital Expansion I/O cards in-
stalled in HD I/O.
Analog I/O
• Up to sixteen channels of 24-bit D/A and A/D
converters for superior analog input and out-
put at sample rates of 44.1 kHz, 48 kHz,
88.2 kHz, 96 kHz, 176.4 kHz, and 192 kHz
with Analog In and Analog Out HD I/O cards
• Soft Clip and Curv limiting circuits to protect
against clipping on analog input.
Digital I/O
• Up to sixteen channels of 24-bit digital I/O,
using AES/EBU, TDIF DB-25, or Optical at
sample rates of 44.1 kHz, 48 kHz, 88.2 kHz, 96
kHz, 176.4 kHz, and 192 kHz with a Digital
HD I/O card
• Real-time sample rate conversion on digital
inputs with a Digital I/O card (up to sixteen
channels of AES/EBU, Optical, or TDIF)
• Support for S/MUX Optical for sample rates of
88.2 kHz and higher
• Support for 2 channels of S/PDIF Optical (en-
closed) with sample rates of up to 96 kHz
• 2 channels of AES/EBU I/O (enclosed) with
support for sample rates up to 192 kHz
• 2 channels of 24-bit-capable S/PDIF I/O (en-
closed) with support for sample rates up to
192 kHz