Focusrite ISA C8X 26x28 USB-C Audio Interface

Focusrite ISA C8X 26x28 USB-C Audio Interface

The Focusrite ISA C8X is a high-performance USB-C audio interface built for professionals and enthusiasts who require extensive I/O, premium analogue character, and seamless integration with patchbays and outboard gear. Featuring a 26x28 configuration, it combines two classic ISA transformer-based mic preamps with six remote-controllable Focusrite mic preamps, delivering exceptional flexibility for studio recording, mixing, and hybrid workflows.

At the heart of the ISA C8X are two Lundahl LL1538 transformer-equipped ISA mic inputs, offering up to 79 dB of gain and stepped and fine controls for precise adjustment. These preamps deliver the renowned ISA sound—clean, detailed, and full of character—while additional Console and 430 Air modes introduce analogue saturation and high-frequency enhancement, adding warmth and presence. The six additional mic preamps provide ultra-low-noise performance with up to 69 dB of gain, ensuring accurate capture across a wide range of sources.

Designed with versatility in mind, the interface includes eight XLR mic inputs, eight balanced TRS line inputs that bypass the preamps for maximum headroom, and 12 balanced outputs supporting configurations up to 7.1.4 monitoring. Dual front-panel Hi-Z instrument inputs feature selectable impedance and run through the same transformer circuitry, making them ideal for guitars, bass, and other instruments.

High-end 24-bit / 192 kHz AD/DA conversion, derived from Focusrite’s RedNet range, ensures pristine audio quality with a wide dynamic range and extremely low distortion. Extensive digital connectivity includes 16 channels of ADAT I/O, S/PDIF, word clock, and MIDI, making it easy to expand your setup or integrate with complex studio systems.

The ISA C8X also offers modern workflow enhancements, including dual independent headphone outputs, detailed LED metering, and full remote control via the Focusrite Control 2 app. Features like automatic gain adjustment and flexible routing streamline session setup, allowing you to focus on capturing performances with speed and precision.

Blending classic analogue tone with advanced digital control, the ISA C8X is a powerful centrepiece for any professional studio environment.

General

• Display: 3x Colour Multi-Segment LED Meter
• Built-In DSP: No
• Maximum Sampling Rate: 192 kHz / 24-Bit
• Number of Microphone Inputs: 8
• Built-In Microphone: No
• Input Level Adjustment: 6x Knob, Automatic

Signal Processing

• Pad: No
• Gain/Trim Range:
  Mic Inputs: Up to 79 dB
  Mic/Line Inputs: Up to 69 dB
• High-Pass Filter: 75 Hz, 18 dB/Octave
• Solo/Mute: No

Connectivity

• Analog Audio I/O:
  8x XLR 3-Pin Balanced Mic Input
  8x 1/4" TRS Balanced Line Input
  2x 1/4" TS Unbalanced Hi-Z Input
  2x XLR 3-Pin Balanced Line/Main Output
  12x 1/4" TRS Balanced Line Output
  2x 1/4" TRS Headphone Output
  2x 1/4" TRS Insert Send
  2x 1/4" TRS Insert Return
• Phantom Power: 48 V, Selectable On/Off (Per Input)
• Digital Audio I/O:
  2x TOSLINK Optical ADAT Input
  1x 3.5 mm Coaxial S/PDIF Input
  2x TOSLINK Optical ADAT Output
  1x 3.5 mm Coaxial S/PDIF Output
• Host Connection / USB: 1x USB-C
• Host Connection Protocol: USB 2.0
• USB (Non-Host): No
• Sync I/O: 1x BNC Word Clock Input, 1x BNC Word Clock Output
• Network I/O: No
• MIDI I/O: 1x DIN 5-Pin Input, 1x DIN 5-Pin Output
• Expansion Slots: No
• Wireless: No

Performance

• Frequency Response: 20 Hz to 20 kHz
• Maximum Input Level:
  Mic/Insert Inputs: +16 dBu
  Line Inputs: +24 dBu
  Hi-Z: +14 dBu
• Maximum Output Level:
  Line Outputs: +24 dBu
  Headphone Outputs: +11 dBu (at 600 Ohms)
• Headphone Output Power:
  130 mW per Channel into 33 Ohms
  14 mW per Channel into 600 Ohms
• Impedance:
  Mic Inputs: 800 to 7000 Ohms
  Hi-Z Inputs: 400 kOhms / 1.2 MOhms
  Headphone Outputs: 3 Ohms
• Dynamic Range:
  Hi-Z Inputs: 117 dBA
  Line Inputs: 120 dBA
  Mic Inputs: 117 dBA (ISA), 116 dBA (Standard)
  Headphone Outputs: 114 dB (33 Ohms), 116 dB (600 Ohms)
  Line Outputs: 125 dBA
• THD+N:
  Mic Inputs: -93 dB / 0.0023% (ISA), -100 dB / 0.001%
  Line Inputs: < -105 dB / 0.00056%
  Hi-Z Inputs: -89 dB / 0.0036%
  Line Outputs: -113 dB / 0.00023%
  Headphone Outputs: -102 dB (33 Ohms), -110 dB (600 Ohms)
• EIN:
  Mic Inputs: -128 dB A-Weighted (ISA), -127 dB A-Weighted

Digital Audio

• Sample Rates: Up to 192 kHz
• Sample Rate Conversion: No
• Bit Depths: 24-Bit
• Sync Sources: MIDI Time Code (MTC), Word Clock
• Clocking: Internal

Audio Storage & Playback

• Media/Memory Card Slot: No

Compatibility

• OS Compatibility: macOS / Windows
• Mobile Device Compatibility: No
• Required Hardware: USB-C Port

Power

• Power Requirements: AC Input
• AC Input Power: 100 to 240 VAC, 50 / 60 Hz
• Power Consumption: 40 W (Max)

Physical

• Rackmount Size: 2U
• Dimensions: 19" / 48.3 cm