Focusrite ISA One Single-Channel Microphone Preamp and DI

ISA One is the single-channel ISA preamp, built for the desk or the bag rather than the rack. The microphone path uses the same Lundahl LL1538 input transformer as the rest of the range, with 0 to 60 dB of gain in 10 dB steps and 20 dB of variable trim above it. Four switchable input impedances let the transformer be loaded to suit a ribbon, a dynamic or a condenser.

The instrument channel is not a shared input: it has its own signal path, 10 to 40 dB of continuously variable gain and high or low impedance settings above 1 megohm or 300 kilohms, so a bass DI and a vocal microphone can run at the same time. A large backlit VU meter with variable calibration handles level, backed by two six-LED peak meters. Add the ISA ADN2 card for digital output.