Focusrite ISA-8CH-A-D CARD 8-Channel A-D Converter Card Optional 8 chan A-D converter fits ISA428 and ISA828 Utilizes Burr-Brown Pro Audio Amplifiers and flagship PCM4220 A-D converter chips AES3 output jitter - &lt;:1500ps, 50Hz-100kHz, &lt;:350ps, 700Hz-100kHz Integrates seamlessly with Pro Tools HD as well as other popular hard disk recorders and mixing desks Can be retrofitted to an ISA428, ISA428 MkII or ISA828 at any time; 2-year limited warranty on manufacturing defects