sE Electronics FluxCore FCA1 Hi-Z Active DI Box W/ Polar Switch

The sE Electronics FluxCore FCA1 is a phantom-powered active DI built for instruments that need the highest possible input impedance. Its switchable Ultra-HiZ input offers up to 10 MΩ, preserving the natural tone, dynamics and full frequency response of passive guitar pickups, piezo-equipped acoustics and other high-impedance sources. Selectable 10 MΩ, 100 kΩ and 10 kΩ settings let you match the input to virtually any instrument or application.

The integrated DYNAMITE gain boost adds +15 or +30 dB of ultra-clean gain right at the source, lifting the signal before long cable runs or electrically noisy environments so every nuance reaches the console. Switchable −15 and −30 dB attenuation pads handle high-output sources such as guitar and bass amplifiers without distortion, and the POLAR switch inverts polarity to resolve phase issues when combining a direct signal with a miked amp.

At its heart is a custom-designed, shielded heavy-duty transformer providing galvanic isolation, high headroom and low distortion. Paired with sE's on⁺ ground lift circuitry, it minimises hum, ground loops and radio-frequency interference for clean, transparent audio across a 10 Hz – 80 kHz frequency range (−0.3 dB).

Built from heavy-gauge steel with a matte-black stealth finish, the FCA1 is compact and road-ready. A non-slip mat, hook-and-loop pads and four rack-mount screws are included, so it sits on a desk, fixes to a pedalboard, or mounts four-up in a single 1U rack space, and the stackable design keeps multi-channel stage setups neat. Front and rear +48 V LEDs confirm phantom power from either side. Requires 48 V phantom power.

• Ultra-HiZ input up to 10 MΩ
  
• Switchable 10 MΩ / 100 kΩ / 10 kΩ impedance
  
• DYNAMITE gain boost: 0 / +15 / +30 dB
  
• Attenuation pad: 0 / −15 / −30 dB