ISA One and 430 Mk II A/D Card

The A/D card is Focusrite's optional stereo analogue-to-digital converter for the ISA One and the ISA 430 Mk II. Fitted inside the host unit, it takes the signal straight from the ISA's own analogue stage into the digital domain, so the transformer-based Focusrite sound reaches your recorder exactly as the preamp produced it, with no extra converter in the chain.

The 24-bit/192kHz Delta-Sigma converter measures 123dB A-weighted with jitter below 20 picoseconds, holding on to every nuance of the analogue signal. AES and S/PDIF outputs run at the full range of sample rates up to 192kHz over a 9-pin D-type connector, while the optical ADAT lightpipe and S/PDIF Toslink outputs cover 44.1, 48, 88.2 and 96kHz, dithered to 16, 20 or 24 bits to suit the destination.

On the ISA One it adds a digital output, turning a classic single-channel preamp into a self-contained front end for a digital studio. On the ISA 430 Mk II it takes the unit from three modular processors to four - mic pre, EQ, dynamics and stereo ADC - with the soft limiter ahead of the converter so it can never be overloaded. Word clock in and out on BNC lets the card lock to standard or 256x external clock, or pass the clock on to the rest of the rig.

The card can be retrofitted to an ISA One or an ISA 430 Mk II at any time.