Focusrite ISA 828 MkII 8-Channel Rack-Mount Transformer-Based Microphone Preamplifier

The Focusrite ISA 828 MkII houses eight iconic transformer-based ISA 110-derived mic preamps in a compact 2U rack unit. Equipped with Lundahl LL1538 input transformers, variable impedance, front-panel instrument inputs, high-pass filters, optional digital expansion, and robust metering, this preamp delivers legendary tone with modern flexibility.

Key Features

• Iso Preamp Design: 8x classic ISA mic preamps with Lundahl LL1538 transformers
• Inputs: Mic/line inputs on all channels; front-panel instrument inputs on channels 1–4 with high/low impedance
• Gain: Up to 60 dB stepped + 20 dB trim (80 dB total) for mic gain; line gain –20 dB to +10 dB + 20 dB trim
• High-Pass Filter: Fixed 75 Hz, 18 dB/octave, per channel
• Metering: Per-channel six-segment LED meters with rear-panel calibration
• Input Impedance: Variable mic impedance—Low (600 Ω), ISA 110 (1.4 kΩ), Medium (2.4 kΩ), High (6.8 kΩ); instrument inputs switch between Low (470 kΩ) and High (2.4 MΩ)
• Insert Points: Switchable rear-panel inserts when used with optional AD card
• Optional A-D Expansion: Supports ISA ADN8 card for Dante, ADAT, AES3 outputs at up to 24-bit/192 kHz
• Power: Internal universal PSU (100–240 VAC), efficient switching design
• Reliability: Updated PSU generates less heat, higher reliability; 3-year warranty

Technical Specifications

• Dimensions: W 482 mm (18.98") x H 88 mm (3.46") x D 325 mm (12.80")
• Weight: 7.05 kg (15.55 lb) – 7.48 kg (16.49 lb) with accessories
• Gain Range (Mic): 0–60 dB stepped + 0–20 dB trim (80 dB total)
• High-Pass Filter: 75 Hz, 18 dB/oct, per channel
• Input Impedance Settings: Mic: 600 Ω / 1.4 kΩ / 2.4 kΩ / 6.8 kΩ; Instrument: 470 kΩ / 2.4 MΩ
• Metering: 6-segment LED, dBFS, rear-trim calibrated
• Power Consumption: 35 W
• Rack Space Required: 2U, with 75 mm rear clearance
• Max Env. Temp: 40 °C (104 °F)

What's Included

• 1x ISA 828 MkII unit
• 1x IEC mains power cable
• 1x Safety cut sheet / quick info
• 3-year Focusrite warranty
• Optional: ISA ADN8 A-D expansion card (sold separately)