With the addition of the Stereo A/D card, the ISA 220 can be used as a high quality mono/stereo tracking converter or at mix down as a stereo converter channel for final mastering.

At the heart of the Stereo A/D card is a high quality 24-bit 96KHz Delta Sigma converter running at 128KHz over-sampling for maximum conversion performance. Focusrite proprietary designs are used for all internal clocking and phase lock loop circuits to guarantee the absolute minimum jitter possible, whether free running or locked to wordclock or ProTools Superclock. When recording to non-24 bit destinations 16 and 20 bit dithering can be selected to ensure the highest quality digital conversion for any format.

The ISAs have two separate channels available for conversion named the INT and EXT with both fed to the A/D inputs, via the Spectral limiter and high resolution LED meter, giving a clean, protected, high quality path to digital.

INT (Internal Signal)

The internal input to the A/D is normally connected to the internal module channel signal passing through the EQ and Dynamics. However, this point can be broken by the rear INT A/D Direct jack and allows a signal to be directly connected to the A/D input (bypassing the internal processing).

EXT (External Input)

The external input (XLR on the rear panel) gives the user access to the second channel of conversion on the A/D card for Stereo recording or for combining signals in Sum mode.

Clock Select

Selectable between 44.1kHz, 48kHz, 88.2kHz and 96kHz.

Bit Rate Select

Selectable between 24, 20 and 16 bits.