Focusrite ISA C8X – 26-in / 28-out USB-C Audio Interface with 2 ISA + 6 Mic Preamps and Comprehensive Analogue & Digital I/O (2U Rackmount)

OVERVIEW

The Focusrite ISA C8X combines the trademark ISA sound with comprehensive remote control and all the analogue and digital I/O, routing, and recallability you need to run your entire setup. The two (2) Lundahl transformer-based ISA preamps feature all-analogue Console and 430 Air modes for new tonal options, alongside switchable impedance, balanced inserts, and high-pass filtering – all controllable from the front panel or via Focusrite Control 2 software.

Designed for modern hybrid studios, ISA C8X delivers the unmistakable character of classic transformer-based preamps alongside powerful digital flexibility. In addition to the two flagship ISA channels, six (6) ultra-low-noise mic preamps provide clean, detailed gain with Air and variable Drive modes, giving you the flexibility to capture everything from transparent recordings to harmonically rich sources. Whether you’re tracking vocals, instruments, or full band sessions, every channel is engineered for precision, depth, and musicality.

With 26 inputs and 28 outputs, flagship 24-bit/192kHz AD/DA conversion, and extensive connectivity including ADAT, S/PDIF, MIDI, and Word Clock, ISA C8X is built to handle complex studio environments with ease. Remote control via Focusrite Control 2 enables seamless routing, gain adjustment, and recall across desktop and mobile, while features like Auto Gain and immersive monitoring support (up to 7.1.4) ensure fast, efficient workflows. It’s a true all-in-one centrepiece for engineers seeking classic analogue tone with modern control and scalability.

KEY HIGHLIGHTS

Classic Preamps, Digital Control

C8X’s two ISA preamps each feature Lundahl LL1538 input transformers that add subtle warmth and body to any signal, plus balanced inserts, stepped and fine gain control, switchable impedance, high-pass filter, and up to 79dB of gain — all digitally controlled via the Focusrite Control 2 app.

All-Analogue Tone

Console mode introduces warm analogue saturation and low-end punch, based on a soft-clip circuit with fully variable digital control. 430 Air, lifted directly from the ISA 430 MkII, adds high-end shimmer via an inductor-based high-shelf filter.

DI Guitars, Basses, and Other Instruments

Inspired by the ISA One’s well-regarded DI channel, the front-panel instrument inputs feature a selectable impedance for preserving the natural tone of guitar, bass, and other instruments. These also run through the ISA transformer circuitry, allowing you to apply both Console and 430 Air modes.

Six (6) Additional Mic Preamps

ISA C8X’s six microphone preamps capture every nuance with 69dB of clear, detailed gain. These too are remotely controllable, designed for reliable performance across a wide range of sources, and each of the feature Air mode for high-end clarity and Drive DSP for analogue-style harmonic warmth.

Flagship AD/DA Conversion

Whichever inputs you choose, you’ll be recording and mixing with the same 24-bit/192kHz AD/DA converters used in Focusrite’s RedNet range, offering 125dB of dynamic range and ultra-low distortion at 0.00022% THD. And C8X’s two headphone outputs each offer independent level control, extra headroom, and optimised impedance for powerful, detailed playback.

Run Your Entire Studio

Designed for patch-bay setups and permanent installations, ISA C8X provides fixed line inputs that let you connect your outboard gear once and avoid awkward re-patching. For immersive formats, the 12 balanced line outputs enable everything from mono up to 7.1.4, with support for up to three monitor groups and switching via both the front panel and Focusrite Control 2. And the entire system is expandable, thanks to 16 additional channels over ADAT and 2 via S/PDIF for digital gear, plus MIDI and Word Clock I/O.

Remote-Control Recording

Focusrite Control 2 is designed for both desktop and mobile devices, making it easy to manage gain levels, route audio, save and recall preset mixes, and monitor with low latency — wherever you install ISA C8X in your studio. It also supports control of multiple connected interfaces simultaneously, so when expanding your setup via ADAT with other Focusrite Control 2-ready devices, you can switch between them and control each one directly from the app.

Backed by Focusrite

ISA C8X is future-proof and designed for reliability. It’s also backed by Focusrite’s three-year warranty and award-winning 24/7/365 technical support for added peace of mind.

Enjoy Three (3) Years of Warranty

Wherever you happen to be in the world, you can rely on a three-year warranty if any Focusrite hardware needs repairing or replacing due to a manufacturing fault.

FEATURES

• 2U rack-mounted, 26×28 USB audio interface: Capture, route, and mix sessions of any size with 26 inputs and 28 outputs of analogue and digital audio.
• Two (2) remote-controllable ISA preamps: Featuring Lundahl LL1538 input transformers that add subtle warmth and body to any signal, plus balanced inserts, stepped and fine gain control, switchable impedance, high-pass filter, and up to 79dB of gain.
• Analogue tone at the touch of a button: The two ISA preamps include relay-switchable circuitry, enabling variable saturation via Console mode and high-end lift with 430 Air mode.
• Six (6) remote-controllable, ultra-low-noise mic preamps: The six additional mic preamps are designed to reliably capture every nuance with 69dB of clear, detailed gain plus Air and variable Drive modes for adding presence and warmth.
• Two (2) front-panel transformer-based instrument inputs: Both are routed through the Lundahl transformers for a console-like feel and feature selectable impedance to enhance the natural tone of guitar, bass, and other instruments. Console and 430 Air modes are also available here for added analogue character.
• Eight (8) dedicated fixed-gain balanced line inputs: Designed for patch-bay setups and permanent installations, ISA C8X provides fixed line inputs that let you connect your outboard gear and avoid re-patching.
• Automatically set your levels: Enable Auto Gain and let ISA C8X set gain automatically across all eight preamps in seconds, directly from the front panel or via Focusrite Control 2 desktop and mobile apps.
• Flagship AD/DA conversion: Record and mix with the same 24-bit/192kHz AD/DA converters used in Focusrite’s RedNet range, offering 125dB of dynamic range with 0.00022% THD.
• 12 balanced line outputs: Work in mono, stereo, or up to 7.1.4, with three monitor groups and front-panel or remote switching. A professional +24dBu maximum output level matches the line inputs for consistent line-up levels, with 125dB of A-weighted dynamic range; outputs 1 and 2 are available on both XLR and TRS.
• Two (2) dedicated class AB headphone outputs: Each with independent level control, extra headroom, and optimised impedance for powerful, detailed playback.
• ADAT, S/PDIF, MIDI, and Word Clock: Expand your setup with 16 additional channels over ADAT and two channels via SPDIF for up to 26 channels of recording, plus S/PDIF, MIDI, and Word Clock connectivity.
• Focusrite Control 2 software and mobile app: When front-panel control isn’t practical, Focusrite Control 2 makes it easy to remotely manage, save, and recall your mixes and routing, as well as monitor with low-latency across multiple connected interfaces.
• Award-winning support: Purchase with confidence. ISA C8X is backed by Focusrite’s three-year warranty and award-winning 24/7/365 technical support

TECHNICAL SPECS:

Hardware Overview

Microphone Preamps: 8

Phantom Power: Yes (Independent per-channel)

Line Inputs: 8

Instrument Inputs: 2

Insert Sends: 2

Insert Returns: 2

Line Outputs: 12

Headphone Outputs: 2

Line Outputs: 10

Headphone Outputs: 2

ADAT Inputs: 2

• 16 channels at 44.1/48kHz
• Up to 8 channels at 96kHz

ADAT Outputs: 2

• 16 channels at 44.1/48kHz
• Up to 8 channels at 96kHz)

SPDIF Input: 1 (2 channels at 96kHz)

SPDIF Output: 1 (2 channels at 96kHz)

MIDI Input: 1

MIDI Output: 1

Word Clock Input: 1

Word Clock Output: 1

Talkback: Yes

Loopback: Yes

Connectivity: USB Type-C

Protocol: USB 2.0

Form Factor: Rack Mountable (2U)

Simultaneous I/O: 26×28 (including Loopback)

A/D Resolution: 24-bit/192 kHz

Maximum Power Draw: 40W

Bus Powered: No

ISA Microphone Inputs (Channels 1-2)

Frequency Response: 20Hz-20kHz (±0.4dB)

Dynamic Range (A-Weighted): 117dB

THD+N (Minimum at Minimum Gain): -93dB (0.0023%)

Noise EIN (A-Weighted): -128dB

Maximum Input Level (Minimum Gain, Low Impedance): +16dBu

Gain Range: 79dB

Input Impedance (Switchable):

• 800Ω (Low)
• 1400Ω (ISA 110)
• 2400Ω (Med)
• 7000Ω (High)

High Pass Filter (HPF):

• 75Hz cut-off frequency
• 18dB/Octave

Microphone Inputs (Channels 3-8)

Frequency Response: 20Hz-20kHz (±0.1dB)

Dynamic Range (A-Weighted): 116dB

THD+N (Minimum at 8dB Gain): -100dB (0.001%)

Noise EIN (A-Weighted): -127dB

Maximum Input Level (Minimum Gain): +16dBu

Gain Range: 69dB

Input Impedance: 3200Ω

Fixed-Level Line Inputs (Channels 1-8)

Frequency Response: 20Hz-20kHz (±0.05dB)

Dynamic Range (A-Weighted): 120dB

THD+N (Minimum): < -105dB (0.00056%)

Maximum Input Level: +24dBu

Instrument Inputs (Channels 1-2)

Frequency Response: 20Hz-20kHz (±0.5dB)

Dynamic Range (A-Weighted): 117dB

THD+N (Minimum): -89dB (0.0036%)

Maximum Input Level (at Minimum Gain): +14dBu

Gain Range: 79dB

Input Impedance (Switchable):

• 400kΩ (Low)
• 1.2MΩ (High)

Inserts (Channels 1-2)

Connection: Balanced

Maximum Output Level (Send): +16dBu

Maximum Input Level (Return): +16dBu

Line Outputs

Frequency Response: 20Hz-20kHz (±0.02dB)

Dynamic Range (A-Weighted): 125dB

THD+N (Minimum): -113dB (0.00023%)

Maximum Output Level: +24dBu

Headphone Outputs

Frequency Response: 20Hz-20kHz (±0.1dB)

Dynamic Range:

• 114dB @ 33Ω
• 116dB @ 300Ω
• 116dB @ 600Ω

THD+N:

• -102dB @ 33Ω
• -110dB @ 300Ω
• -110dB @ 600Ω

Max Output Level:

• +8dBu @ 33Ω
• +11dBu @ 300Ω
• +11dBu @ 600Ω

Max Output Power:

• 130mW @ 33Ω
• 28mW @ 300Ω
• 14mW @ 600Ω

Output Impedance: 3Ω

Compatibility

Windows (Processors Supported):

• Intel
• AMD
• ARM64

MacOS (Processors Supported):

• Apple Silicon
• Intel

Linux (Processors):

• ISA C8X is UAC2 class compliant
• Should work on most Linux systems, but this is not tested or supported

System Requirements: Visit Focusrite’s official website for the latest information on supported Windows, Mac, and iOS operating systems.

Dimensions

Height: 89mm (3.50″)

Width: 482.6mm (19.00″)

Depth: 292.8mm (11.53″)

Weight

Without Accessories: 5.558kg (12.26 lbs)

With Accessories: 5.826kg (12.85 lbs)

WHAT’S IN THE BOX?

• 1 x ISA C8X Audio Interface
• 1 x USB Type C-to-C Cable
• 1 x Region-Specific IEC Cable
• 4 x Rubber Feet