The Atoll PR400 EVO preamplifier is the French manufacturer's most ambitious preamp. It was designed to fit into a very high-quality hi-fi system. It is of course also designed to be combined with the Atoll AM 400 EVO power unit, but it is fully compatible with other prestigious electronics.
Atoll PR400 EVO : façade
The Atoll IN400 EVO preamp has swapped its original half-panel front for a much more traditional finish. We find the traditional front panel cut from a 10mm thick anodized aluminum plate (Silver or Black)! The chassis is made of 2mm thick steel. The side heatsinks are machined from solid aluminum blocks that absorb mechanical vibrations and ensure perfect heat dissipation of the components. With the weight of the card and power transformers, the PR400 EVO weighs 15kg on the scale!
At the center of the front is a window housing a low-power blue OLED display. On each side, there is a large logic potentiometer made of solid aluminum: the one on the right controls the volume (by rotation) and the balance (by pressing), while the one on the left controls the source selection (by rotation) and the power (by pressing). It is worth noting that there is a backlight around these two buttons that can be set to red, blue, or purple.
In addition to the buttons, there is a 6.35 mm headphone jack on the front.
The remote control is complete and includes all the functions as well as some of the manufacturer's other products (CD, Drive, Dac etc.)
Atoll PR400 EVO: Rear panel
On the back, the Atoll PR400 EVO offers a total of 5 unbalanced analog inputs in RCA format. In addition, there are two balanced inputs in female XLR format and, of course, two balanced outputs in male XLR format.
These bipolar symmetrical stages are entirely made with very low tolerance discrete components. In addition to these inputs, there are 2 pre-outs, a By-Pass and a Tape Out.
The IN400 EVO integrated amplifier can also be equipped with an Atoll DA 200 digital card. The latter, as an option, offers a PCM DAC: 32 bits – 768kHz! It is accessible via 6 digital inputs: 2 coaxial, 2 optical and one USB-B. It should be noted that the USB DAC is an XMOS USB: XHRA-2HPA with a program specifically developed for Atoll.
Atoll PR400 EVO: characteristics
The internal architecture is impressive! The chassis is as solid as an egg! This Atoll amp is fully dual mono. Even the star grounds are differentiated for each channel.
The PR400 EVO is powered by 4 toroidal transformers. Filtering is provided by a bank of chemical capacitors dedicated to audio, totaling more than 112,000 uF of capacity! The analog stages receive high-end MKP capacitors, shielded in independent enclosures to avoid any radiation problems.
Each component was selected by listening and the schematic optimized to precisely refine the bias currents of the bipolar transistors and the very low feedback.
The PR400 EVO operates in dual mono (two low-noise linear transformers per channel) and in pure balanced mode. The selection relays are also separate for the two channels. The volume is controlled by two independent and perfectly synchronized motorized ALPS potentiometers. Atoll uses a proprietary servo system, based on non-intrusive real-time measurement of the audio signal.
Atoll PR400 EVO: test and listen
With the Atoll PR400 EVO, we never feel like it alters the signal significantly. On the contrary, this preamplifier offers a very clean and neutral reproduction. Transparency is excellent, micro-details are reproduced with precision and clarity. Despite this remarkable clarity, the PR400 EVO displays accurate and full timbres. The percussion and strings have substance, and the vocals are reproduced with a beautiful presence and a remarkable organic form.
In terms of dynamics and breadth, the Atoll PR400 EVO preamplifier is truly impressive. The stereo and soundstage allow for total immersion in the music.
With its 400 Signature series, the manufacturer Atoll is establishing itself more than ever as a major player in high-end separate amplification.
This Atoll PR400 preamplifier offers remarkable potential and performance. This PR400 EVO is well worth its price in terms of manufacturing, technology, performance and musicality!
It deserves to be considered before any purchase in this price range… Especially since I don't really see any competition...
Our favorite
FranckAnalog Power Supply: 2 x 10 VA linear
Digital Power Supply: 10 VA + 1.6 VA Linear
Total capacitive: 112,000 µF
RCA analog inputs: 5
XLR analog inputs: 2
RCA analog outputs: 2
XLR analog outputs: 2
BY-PASS input: 1
Sortie Tape : 1
Input impedance: 357 kOhms
Sensitivity: 4V
Signal-to-noise ratio: 100 dB
Distortion at 1kHz: 0.004%
Bandwidth: 0.5Hz - 780kHz
Rise time: 0.4 µs
Dimensions : 440 x 130 x 370 mm
Weight: 15 kg
