Atoll IN400 EVO

The Atoll IN400 Evolution (EVO) is the flagship integrated amplifier from French audio manufacturer Atoll Electronique. Built entirely by hand in Brecey, Normandy, it sits at the pinnacle of Atoll's core electronics lineup, combining high current delivery, a fully symmetrical dual-mono architecture, and modular connectivity.

Core Architecture & Power Supply

• Power Output: Delivers 160 W RMS per channel into 8 Ω and 300 W RMS per channel into 4 Ω in Class A/B, capable of driving demanding, low-impedance loudspeaker loads.

• Power Supply: Houses a massive 1,050 VA toroidal transformer dedicated exclusively to the audio stages, alongside an independent 1.6 VA transformer for the logic and control circuits. Total power supply capacitance reaches 96,680 µF.

• Dual-Mono Symmetry: True dual-mono internal structure with separate windings per channel and matched MOS-FET output transistors (8 per channel).

• Independent Attenuation: Features two separate switched-resistor volume attenuators—one dedicated to each channel—to preserve channel separation and avoid stereo crosstalk.

• Speed & Bandwidth: Exhibits a very fast 2 µs rise time and an extended frequency bandwidth from 5 Hz to 100 kHz (-3 dB), ensuring sharp transient dynamics and articulate bass impact.