The Focusrite ISA C8X is a 2U rack-mounted 26-in, 28-out USB-C audio interface built around eight remote-controlled preamps, two of which are ISA transformer preamps featuring classic Lundahl LL1538 transformers. Born from the original 1985 Rupert Neve circuit commissioned by Sir George Martin, these two ISA preamps deliver warm, rich character with up to 79 dB of gain, switchable impedance (800 Ω–7 kΩ), balanced inserts, and high-pass filtering. All-analogue Console and 430 Air modes — lifted directly from the ISA 430 MkII — provide tonal shaping without any DSP processing. Six additional Focusrite preamps offer 69 dB of gain per channel, analogue Air mode for added presence, and variable Drive for harmonic saturation. The interface achieves 24-bit/192kHz conversion with up to 125 dB of dynamic range using the same AD/DA converters found in Focusrite's flagship RedNet range. Twelve balanced line outputs with three monitor groups support setups from stereo all the way to 7.1.4 immersive audio. Two ADAT optical ports add up to 16 channels of digital expansion, while S/PDIF, MIDI, and Word Clock connectivity make ISA C8X the clock and MIDI hub of any professional studio. The multichannel Auto Gain function sets optimal levels across all eight preamps simultaneously, and standalone mode allows full audio routing without a connected computer.

Key Specifications

I/O: 26-in / 28-out (USB-C, USB 2.0)

Preamps: 8 total — 2x ISA with Lundahl LL1538 transformers (up to 79 dB), 6x Focusrite (up to 69 dB)

Conversion: 24-bit / 192 kHz, up to 125 dB dynamic range

Digital I/O: 2x ADAT (16 ch @ 44.1/48 kHz), S/PDIF, MIDI, Word Clock

Form Factor: 2U rack-mount, 482.6 × 292.8 × 89 mm, 5.56 kg