Focusrite ISA One Classic Single-Channel Mic Preamp

Description

The Focusrite ISA One Classic is a premium, single-channel microphone preamplifier that delivers the legendary Focusrite sound — inspired by the original ISA 110 preamp design from the iconic Focusrite Studio Console. It combines a transformer-based mic preamp, independent DI channel, and flexible I/O routing, making it a studio favorite for capturing vocals, instruments, and line-level sources with exceptional warmth and clarity.

Key Features

• Legendary Focusrite Transformer-Based Mic Preamp – Derived from Rupert Neve’s classic ISA 110 circuit, delivering vintage analog warmth and precision.

• Variable Input Impedance – Four impedance settings (Low, ISA 110, Medium, High) to perfectly match any microphone or instrument.

• Independent Instrument (DI) Input – Discrete, high-quality DI with dedicated gain and output for direct instrument recording.

• Professional Conversion (Optional Digital Card) – Expandable with an optional A/D converter card for up to 24-bit / 192 kHz digital output via AES/EBU, S/PDIF, or ADAT.

• Dedicated Headphone Output – With independent mix control for zero-latency monitoring.

• Analog VU Meter & LED Peak Metering – Accurate metering for both mic and DI signals.

• Insert Point – Allows use of external compressors or EQ before A/D conversion.

• Robust Portable Chassis – Desktop or rack-mountable design for flexible studio integration.

Technical Specifications

• Inputs:

  • 1 × XLR mic input (transformer balanced)

  • 1 × TRS line input

  • 1 × ¼″ instrument (DI) input

• Outputs:

  • 1 × XLR line output

  • 1 × TRS line output

  • 1 × DI output (XLR and TRS)

  • ¼″ headphone output

• Frequency Response: 20 Hz – 20 kHz ±0.1 dB

• Dynamic Range: 120 dB (A-weighted)

• Equivalent Input Noise: -126 dB

• THD+N: < 0.001%

• Phantom Power: +48V

• Impedance Settings: 600Ω, 1.4kΩ (ISA 110), 2.4kΩ, 6.8kΩ

• Power Supply: Internal (100–240V AC)