Focusrite ISA One

Mono preamplifier with Mic, Line and Instrument DI input

• ISA preamplifier with Lundahl LL1538 transformer
• Impedance selectable to four levels, including ISA110
• Independent DI channel with dedicated amp and XLR output
• Backlit VU meter, insert point, high-pass filter
• Optional 192kHz stereo A-D converter
• Headphone output with volume and stereo cue mix

Focusrite ISA One: classic mic preamp with modern flexibility

ISA One is a mono preamplifier from Focusrite's ISA series, based on the iconic ISA110 circuit and equipped with Lundahl LL1538 transformer. Its unique sound response, inherited from legendary Focusrite consoles, is ideal for classic microphones and professional studio or live applications. The rugged portable chassis also makes it perfect for mobile set-ups.

Variable impedance and sonic versatility

The heart of the ISA One is its transformer input stage, which adds warmth and character. Added to this classic foundation is a modern feature: the ability to select one of four input impedances, including the original ISA110. This allows optimal or creative matching with any microphone, from vintage to transparent.

Independent DI channel for instruments and flexible routing

The DI channel is completely independent, with high/low impedance switching, dedicated gain control, amplifier output and separate XLR on the back. The ISA One is ideal for guitarists, producers, and engineers who wish to record microphone and DI in parallel, or combine vocals and instrument in one professional unit.

Control, monitoring and digital conversion

ISA One includes insert points for adding EQ or compressors, a backlit VU meter with variable calibration, and two LED peak meters. The headphone output allows direct monitoring or listening to an external stereo cue mix via rear TRS inputs. An optional 24-bit / 192kHz A-D converter with 118 dB dynamic range is also available.

Emulation in plugins: ISA sound even in DAWs

With Brainworx's bx_console Focusrite plugin, you can bring the sound of Focusrite consoles into your DAW. Based on the ISA110 and ISA130 modules, it faithfully captures the warmth and openness of the original sound, providing a vintage feel in your digital mixes.

Technical specifications.

• Mic gain: 0-60 dB in steps of 10 dB + 20 dB variable
• EIN (mic): -126 dB at 60 dB gain
• S/N (mic): 106 dB over headroom
• Frequency response (mic): -0.5 dB at 10 Hz / -3 dB at 125 kHz
• CMRR: 98 dB @ 1kHz
• Line gain: -20 dB to +10 dB + 20 dB variable
• Line impedance: 10 kΩ
• THD (line): 0.0001
• Instrument gain range: 10-40 dB
• Instrument impedance: High >1MΩ / Low >300kΩ
• High-pass filter: 75 Hz, 18 dB/octave
• Optional converter: 24 bit / 192kHz, 118 dB dynamic