Atoll Electronique PR400 Evolution silver

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 the introduction of a low-power mode. Designed and manufactured in France, this preamplifier showcases French craftsmanship in high-fidelity, blending artisanal tradition with contemporary technologies to deliver exceptional musical reproduction.

Handcrafted Construction: French Excellence in Every Detail

The front panel of the PR400 Evolution immediately reveals Atoll Electronique’s design philosophy. The 10 mm brushed, bead-blasted, and anodized aluminum features high-precision engraving, reflecting a typically French attention to detail. This artisanal approach is also evident in the heat sinks and knobs, machined from solid metal, with each element contributing to the overall aesthetic and functional harmony.

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

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 each channel has its own toroidal transformer, ensuring perfect isolation between the left and right channels. The four independent audio stages, designed with perfectly symmetrical architecture, eliminate any unwanted interaction and deliver remarkably precise stereo reproduction.

The input stages use bipolar transistors, paired with current sources also based on bipolar transistors and LEDs, ensuring exemplary linearity. The very low negative feedback, characteristic of the best audiophile electronics, preserves the naturalness of the musical message while maintaining perfect stability. This technical approach results in 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 takes 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 a 1.6 VA transformer for digital control logic. This multiplication of power supplies eliminates any interaction between the device’s different sections, ensuring the purity of the audio signal.

A total capacitance of 112,000 µF provides a considerable energy reserve, guaranteeing dynamics and control during the most demanding musical passages. High-quality MKP coupling capacitors, shielded to eliminate parasitic electromagnetic radiation, contribute to this quest for absolute purity. Such attention to power supply detail, rare in this price range, reflects Atoll Electronique’s uncompromising approach.

High-Precision Volume Control: Motorized ALPS Technology

The PR400 Evolution’s volume control system uses two motorized ALPS potentiometers, one per channel, ensuring perfect channel matching. This technical solution, more complex than a traditional stereo potentiometer, provides exemplary adjustment precision and superior longevity. The motorized system also allows for remote control and memory of settings, adding appreciable user convenience.

Precise balance adjustment, with memory capability, demonstrates attention to practical details. This feature, often overlooked in preamplifiers of this range, allows for perfect adaptation to the room’s acoustic characteristics or user preferences. The quality of ALPS potentiometers, a global reference in this field, guarantees long-term precision and reliability.

Modern User Interface: OLED and Customization

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

The ability to rename inputs adds a valuable practical dimension, especially in complex setups. Customizable button backlighting enhances the unit’s elegance while making operation easier in low-light conditions. These ergonomic details, often neglected in the high-fidelity world, reflect a holistic design approach where functionality and aesthetics harmoniously complement each other.

Intelligent Power Management: Ecological Innovation

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

This technical innovation allows the device’s behavior to be adapted to listening habits: low-power mode for occasional use, preheating mode for demanding audiophiles seeking immediate optimal performance. This intelligent approach to energy consumption positions the PR400 Evolution as an environmentally friendly product without sacrificing technical excellence.

Comprehensive Connectivity: Analog and Digital Versatility

The PR400 Evolution’s connectivity meets the demands of the most complete setups. The seven inputs include five line-level RCA inputs (AUX or PHONO optional, CD, TUNER, DVD, TAPE) and two balanced XLR inputs. This wealth of options allows simultaneous connection of all sources in a demanding audiophile system, from CD player to external DAC and turntable.

The bypass input makes integration into an existing home theater system easy, allowing you to enjoy the PR400 Evolution’s quality for stereo listening while retaining 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 power-up of other equipment.

Digital Scalability: DA100 and DA200 Cards

The PR400 Evolution anticipates the evolution of digital sources with 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 control center. The DA200 card further enhances this connectivity with the same optical and coaxial inputs, plus an asynchronous USB input compatible with DSD and Bluetooth connectivity.

This modularity is a long-term investment, allowing the PR400 Evolution to adapt to future technological developments without replacing the entire device. The modular architecture reflects a long-term vision, characteristic of manufacturers committed to product durability. This scalable approach protects the initial investment while offering expansion possibilities according to needs and budget.

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
• Option to rename inputs
• Choice of standby mode: low power consumption 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 consumption mode.
• High-fidelity equipment designed and manufactured in France.