Atoll Electronique PR400 Signature silver

The PR400 Signature operates in dual mono with a low-noise transformer per channel. The potentiometers and selection relays are also separated for both channels. The coupling capacitors (high-end MKP selected by listening) are shielded in independent housings to avoid any radiation issues. The filtering totals 55,000µF per channel.

Volume control is achieved by two motorized ALPS potentiometers, independent and perfectly synchronized. We use a proprietary servo system based on real-time, non-intrusive audio measurement.

The audio stages are designed symmetrically: 2 identical stages per channel.

In addition, these discrete component stages have a purely symmetrical power supply structure; the circuit is based on a double differential input pair and an original class A polarized design with very low negative feedback. This structure minimizes both overall distortion and intermodulation distortion, enhancing spatial perception and instrument materiality.

The display used is a low-power OLED model chosen for its excellent contrast and low electromagnetic radiation. Moreover, its power supply, as well as those of all control components, is completely independent of the audio power supplies.

The principle of rigorously symmetrical operation ensures nuanced and highly detailed musicality with an evident ability to separate performers and different registers. The PR400 Signature has the ability to present homogeneous musicality regardless of the listening level. The care taken in the slightest adjustments and component selection makes it possible to perceive the faintest breath and the performers’ intentions with surprising clarity and naturalness; the most subtle nuances and timbre subtleties are perfectly intelligible.

Technical Specifications

Electrical Specifications

• Analog power supply: 2 × 10 VA
• Digital power supply: 1 × 10 VA
• 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
• Total capacitance: 112,000 µF

Connectivity

• 6 stereo inputs: auxiliary (AUX), CD, tuner (TUNER), DVD, tape (TAPE), bypass (BY-PASS)
• 2 balanced inputs: XLR1, XLR2
• Outputs:
  • Fixed: tape output (TAPE OUT)
  • Variable: 2 stereo, 2 balanced, 6.35 mm headphone

Physical Characteristics

• Remote control included
• Dimensions (W × H × D): 440 × 130 × 370 mm
• Weight: 11 kg

Digital-to-Analog Converter (DAC) Module (optional)

• Bluetooth receiver with direct digital link to AKM converter
• Digital inputs:
  • 2 coaxial (24-bit / 192 kHz)
  • 2 optical (24-bit / 192 kHz)
  • 1 USB-B for pulse-code modulation (PCM) and delta-sigma modulation (DSD)
• Audio converter: AKM - AK4490
• Compatibility:
  • PCM: 16 to 32 bits up to 384 kHz (asynchronous USB-B)
  • DSD: DSD64, DSD128
• USB XMOS interface with specific ATOLL program