Atoll Electronique PR400 Evolution black

The PR400 Evolution marks Atoll Electronique’s entry into 2025 with a completely redesigned stereo preamplifier. This new model embodies French expertise in audiophile electronics, featuring significant technical innovations: new design, reworked power supplies, improved audio performance, and introduction of a low-consumption mode. Designed and manufactured in France, this preamplifier showcases French craftsmanship in high-fidelity audio, combining traditional artisanal skills with contemporary technologies to deliver exceptional musical reproduction.

Artisanal construction: French excellence in every detail

The front panel of the PR400 Evolution immediately reveals Atoll Electronique’s construction philosophy. The 10mm aluminum, brushed, micro-beaded and anodized, features high-precision engraving that demonstrates a typically French attention to detail. This artisanal approach is reflected in the heat sinks and knobs machined from solid material, with each element contributing to the aesthetic and functional harmony of the whole.

The 2mm steel chassis ensures exemplary structural rigidity, essential for preserving audio signal integrity from parasitic vibrations. This massive construction, bringing the total weight to 15 kg, illustrates a philosophy where mechanical solidity directly contributes to sound quality. French manufacturing ensures rigorous quality control and local technical support, decisive advantages in the high-fidelity universe.

Full dual-mono architecture: perfect channel separation

The technical heart of the PR400 Evolution is based on a particularly sophisticated full dual-mono structure. This design means that each channel has its own toroidal transformer, guaranteeing perfect isolation between left and right channels. The four independent audio stages, designed with perfectly symmetrical structure, eliminate any parasitic interaction and ensure stereophonic reproduction of remarkable precision.

The bipolar transistor input stages, combined with current sources also using bipolar transistors and LEDs, guarantee exemplary linearity. The very low negative feedback, characteristic of the finest audiophile electronics, preserves the naturalness of the musical message while maintaining perfect stability. This technical approach translates into a wide and coherent soundstage, where each instrument finds its natural place in the reproduced acoustic space.

Quadruple power supply: four transformers for absolute purity

The PR400 Evolution’s power supply adopts a particularly ambitious approach with its four dedicated toroidal transformers. The architecture includes two 10 VA transformers for the analog audio sections, complemented by a 10 VA transformer and another 1.6 VA transformer for the digital control logic. This multiplication of power supplies eliminates any interaction between the different sections of the device, guaranteeing audio signal purity.

The total capacitance of 112,000 µF ensures considerable energy reserve, guaranteeing dynamics and stability during the most demanding musical passages. The high-quality MKP coupling capacitors, shielded to eliminate parasitic electromagnetic radiation, contribute to this absolute pursuit of purity. This attention to power supply details, rare in this price range, demonstrates the uncompromising approach characteristic of Atoll Electronique.

High-precision volume control: motorized ALPS technology

The PR400 Evolution’s volume control system uses two motorized ALPS potentiometers, one per channel, guaranteeing perfect channel matching. This technical solution, more complex than a traditional stereo potentiometer, ensures exemplary adjustment precision and superior longevity. The motorized system also enables remote control and setting memorization, adding appreciable user convenience.

The precise balance adjustment, with memorization capability, reveals the attention paid to practical details. This function, often neglected in preamplifiers in this range, allows perfect adaptation of listening to the room’s acoustic characteristics or user preferences. The quality of ALPS potentiometers, a world reference in this field, guarantees long-term precision and reliability.

Modern user interface: OLED and customization

The PR400 Evolution’s interface reconciles audiophile tradition with technological modernity. The high-contrast OLED display offers perfect readability while preserving installation aesthetics thanks to its extinction mode after five seconds of inactivity. This balanced approach respects purists who prefer discrete displays while providing necessary information during adjustments.

The ability to rename inputs adds appreciable practical dimension, particularly in complex installations. The configurable backlighting of buttons contributes to the overall elegance while facilitating use in reduced lighting conditions. These ergonomic details, often neglected in the high-fidelity universe, demonstrate a comprehensive design approach where functionality and aesthetics complement each other harmoniously.

Intelligent energy management: ecological innovation

The PR400 Evolution introduces intelligent energy management with its dual standby mode. Users can choose between a low-consumption mode, significantly reducing electrical consumption in standby, or a preheating mode maintaining audio circuits at optimal temperature. This flexibility addresses contemporary ecological concerns without compromising audiophile performance.

This technical innovation allows adapting the device’s behavior to listening habits: low-consumption mode for occasional use, preheating mode for demanding audiophiles wanting immediate availability of optimal performance. This intelligent approach to energy consumption positions the PR400 Evolution as an environmentally respectful product without renouncing technical excellence.

Comprehensive connectivity: analog and digital versatility

The PR400 Evolution’s connectivity satisfies the requirements of the most complete installations. The seven inputs include five line inputs on RCA (AUX or PHONO optional, CD, TUNER, DVD, TAPE) and two balanced inputs on XLR. This richness allows simultaneously accommodating all sources of a demanding audiophile installation, from CD player to external DAC including turntable.

The bypass input facilitates integration into an existing home cinema system, allowing users to benefit from the PR400 Evolution’s quality for stereo listening while maintaining surround functionality. Multiple outputs (one TAPE output, two XLR outputs and two stereo line outputs) offer maximum flexibility for connecting recorders, multiple amplifiers or bi-amplification systems. The 12V trigger output enables installation automation by controlling the startup of other equipment.

Digital evolution: DA100 and DA200 cards

The PR400 Evolution anticipates digital source evolution through its optional DA100 and DA200 cards. The DA100 card adds four digital inputs (two optical and two coaxial), transforming the preamplifier into a true digital command center. The DA200 card further enriches this connectivity with the same optical and coaxial inputs, complemented by an asynchronous USB input compatible with DSD and Bluetooth connectivity.

This modularity constitutes a sustainable investment, allowing adaptation of the PR400 Evolution to future technological developments without replacing the entire device. The modular architecture demonstrates long-term vision, characteristic of manufacturers concerned with product durability. This evolutionary approach protects the initial investment while offering extension possibilities according to needs and budgets.

Frequently asked questions

What is the difference between the optional DA100 and DA200 cards? The DA100 card offers four digital inputs (two optical and two coaxial), while the DA200 adds to these same connectivities an asynchronous USB input compatible with DSD and Bluetooth connectivity. The choice depends on the digital sources to connect and available budget.

Does the low-consumption mode affect audio performance? No, the low-consumption mode only acts on standby and control circuits. Users can alternate between low-consumption mode and preheating mode according to their listening habits, without impact on sound quality during operation.

Can XLR and RCA outputs be used simultaneously? Yes, the PR400 Evolution has independent XLR and RCA outputs, allowing simultaneous connection of multiple amplifiers or use in bi-amplification. This flexibility facilitates progressive installation evolution.

Does the BY-PASS function preserve audio quality? The BY-PASS input allows home cinema integration by short-circuiting the preamplifier’s processing circuits. This function maintains signal integrity for applications where volume control is performed upstream.

Do the toroidal transformers require particular break-in? Like most high-quality audiophile equipment, the PR400 Evolution benefits from a break-in period allowing components to reach optimal performance. The toroidal transformers participate in this progressive maturation.

Can different balance settings be memorized according to sources? The system allows memorization of balance settings, facilitating adaptation to different recording characteristics or personal preferences. This practical function avoids repetitive readjustments when changing sources.

Technical Specifications

Construction and Design

• 10 mm brushed, microbead-blasted, and anodized aluminum front panel with high-precision engraving
• Heatsinks and knobs machined from solid aluminum
• 2 mm steel chassis
• Four toroidal transformers: 2 × 10 VA (audio) + 10 VA and 1.6 VA (logic)
• High-quality shielded MKP coupling capacitors

Audio Architecture

• Fully dual-mono structure:
  • Two toroidal transformers: one per channel
  • Four independent audio stages with perfectly symmetrical structure
  • Two motorized ALPS potentiometers: one per channel
• Bipolar transistor input stages
• Current sources with bipolar transistors and LEDs
• Audio stages with perfectly symmetrical structure, very low negative feedback

Features

• Precise balance adjustment with memory function
• Ability to rename inputs
• Selectable standby mode: low power or preheating
• Configurable button backlighting
• High-contrast OLED display: on or off mode (after 5 seconds of inactivity)

Technical Specifications

• Analog power supply: 2 × 10 VA linear
• Digital power supply: 10 VA and 1.6 VA linear
• Total capacitance: 112,000 µF
• Number of inputs: 5 line + 2 XLR
• Input impedance: 357 kΩ
• Sensitivity: 4 V
• Signal-to-noise ratio: 100 dB
• Distortion at 1 kHz: 0.004%
• Bandwidth: 0.5 Hz - 780 kHz
• Rise time: 0.4 µs

Connectivity

• Inputs:
  • 2 XLR inputs
  • 5 line inputs: AUX or PHONO (optional), CD, TUNER, DVD, TAPE
  • 1 bypass input
• Outputs:
  • 1 TAPE output
  • 2 XLR outputs
  • 2 stereo line outputs
  • 1 12 V trigger output

Optional Boards

• Option to add DA100 and DA200 digital boards:
  • DA100:
    • 2 optical inputs
    • 2 coaxial inputs
  • DA200:
    • 2 optical inputs
    • 2 coaxial inputs
    • 1 asynchronous USB and DSD input
    • 1 Bluetooth input

General Information

• ATOLL universal remote control included as standard
• Dimensions: 440 × 370 × 130 mm
• Weight: 15 kg

General Information

• New design, reworked power supplies, improved audio performance, low power mode.
• High-fidelity equipment designed and manufactured in France.