Focusrite ISA Two 2‑Channel Rack‑Mount Microphone Preamplifier

The Focusrite ISA Two brings two independent, legendary ISA 110‑derived microphone preamps into a compact 1U rack format. Combining Lundahl LL1538 transformer input stages with rotary gain control and variable impedance, it offers both the classic Focusrite warmth and modern flexibility for high-quality analog signal capture.

Each channel features front‑panel instrument and rear‑panel line/mic inputs, switchable impedance, individual high‑pass filters, inserts, and LED metering calibrated via rear‑panel trim—making it a powerful studio-quality unit for vocal, instrument, or stereo tracking.

Key Features

• Inputs: Mic (XLR), Line (TRS), front-panel DI (¼″ TS); switchable input impedance (Low: 600 Ω, ISA 110: 1.4 kΩ, Medium: 2.4 kΩ, High: 6.8 kΩ)
• Gain: Up to 80 dB of clean gain (60 dB stepped + 20 dB trim)
• High-Pass Filter: Smooth 18 dB/octave filter, variable from 16 Hz to 420 Hz
• Inserts: Balanced insert send/return per channel for external processing
• Metering: Front-panel 8‑segment LED meters with rear-panel calibration
• Transformers: Lundahl LL1538 input transformers—same as the original ISA 110 design
• Connectivity: Rear-panel mic, line, insert, and output jacks; IEC power input, calibration knob
• Power & Environment: Internal universal power supply (100–240 VAC, 35W). 1U rack height; requires ~75 mm rear clearance; max ambient temp 40 °C
• Warranty: 3‑year manufacturer’s warranty

Technical Specifications

• Dimensions: 19.0" (W) × 12.8" (D) × 1.7" (H) (~482 × 325 × 44 mm)
• Weight: 3.7 kg (8.12 lb)
• High-Pass Filter: 18 dB/octave, 16–420 Hz
• Maximum Gain (Mic): Up to 80 dB total
• Operating Power: 100–240 VAC, 35 W

What's Included

• 1x ISA Two 1U rack-mounted mic preamp unit
• 1x IEC mains power cable