The optional A/D card can be factory fitted or
purchased later and retro fitted as and when required, to suit your
recording budget.With the addition of the Stereo A/D card the ISA 220
can be used as high quality mono/stereo tracking converters 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 oversampling 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.
