The AV500 from Atoll Electronique is a multichannel amplifier designed for home theater installations. It delivers 85 watts per channel at 8 ohms across five channels, and can provide 100 watts at 8 ohms in two-channel mode. Its design features a symmetrical architecture with discrete components and a power supply sized to meet energy demands.
The AV500 embodies Atoll’s technical philosophy: fully symmetrical stages with discrete components. This approach, more complex to implement than using integrated operational amplifiers, allows designers to control every parameter of the circuit. The transistors are precisely biased, often in class A for the input stages, ensuring optimal signal linearity.
The choice of MOS-FET transistors for the output stage is worth highlighting. These components have unique electrical characteristics: their very high input impedance (several megaohms) makes them easy to drive, while their temperature behavior remains stable. Unlike conventional bipolar transistors, MOS-FETs have an on-state resistance (RdsON) that increases with temperature, creating a self-regulating thermal effect that benefits long-term reliability.
The power supply is the energetic heart of the device. Two 340 VA toroidal transformers power the five channels. This dual-transformer configuration, rather than a single 680 VA unit, offers several advantages: better distribution of magnetic flux, reduced interference between channels, and increased stability during consumption peaks. Filtering reaches a total of 73,000 microfarads, or about 14,600 µF per channel—a substantial value that ensures a significant current reserve for musical transients.
The 4 mm thick brushed aluminum front panel displays the brand’s characteristic sobriety. Only the Atoll logo and a status LED break up this slightly curved, uniform surface. This unusual thickness for a front panel contributes to the overall rigidity and limits unwanted vibrations.
The 1.5 mm steel chassis forms a robust structure, perforated with multiple ventilation holes arranged in concentric patterns on the top and sides. This passive ventilation, designed to dissipate heat from the power transistors, allows for fanless operation—guaranteeing absolute silence in use.
All connections are located on the rear panel. Five gold-plated RCA inputs correspond to the five channels, accompanied by five RCA outputs for daisy-chaining to other amplifiers or for bi-amping. The screw speaker terminals accept banana plugs and offer a generous section to accommodate large-diameter cables. The IEC power socket allows the original power cord to be replaced.
The unit measures 440 mm wide, 291 mm deep, and 95 mm high, with a weight of 12 kg. These compact dimensions for a five-channel amplifier make it easy to integrate into a standard hi-fi cabinet.
The AV500 naturally finds its place alongside a home theater amplifier equipped with pre-out outputs. In this configuration, it handles amplification for the front left/right and surround channels, freeing the main amplifier to power only the center, surround back, or height channels. This distribution improves the system’s overall dynamics by reducing the thermal and electrical load on each device.
The AV500’s gain is matched to that of Atoll’s AM and AV series, making integration into an evolving system easy. The input sensitivity, between 1.58 and 1.77 V, meets market standards, ensuring compatibility with most preamplifiers and processors.
A practical detail: the version without a trigger requires manual power-on via the rear switch. For advanced installations, Atoll offers a version with a 12V trigger input, allowing automatic power-on from the home theater processor—an option available from the factory for an additional 60 euros.
The AV500’s versatility allows it to be used as a high-power stereo amplifier. In this mode, only two channels are used, delivering 100 watts at 8 ohms or 140 watts at 4 ohms. The transformers and capacitors then operate with a comfortable margin, optimizing dynamic performance during complex passages.
Thanks to its MOS-FET transistors and generous power supply, the AV500 maintains stability with complex loads. The 73,000 µF filtering capacity ensures a sufficient current reserve for fluctuating impedances. The 100 watts available at 4 ohms per channel demonstrate its ability to drive speakers with average sensitivity.
Technically possible, this setup requires gain matching. The AV500’s input sensitivity (1.58–1.77 V) is within market standards. However, pairing Atoll amplifiers together ensures optimal gain consistency and sonic signature, as the circuits are designed to work together.
The thermal design relies on passive dissipation via the ventilated chassis and internal heat sinks. In normal use, even during sustained passages, the temperature remains controlled. A ventilation space of 10 cm above and to the sides is sufficient. MOS-FET transistors have the advantage of self-regulating thermally, as their resistance increases with temperature.
These outputs pass through the input signal without amplification. They allow you to daisy-chain multiple amplifiers for multiroom setups or to bi-amp compatible speakers. In the latter case, one channel powers the bass, the other the treble of the same speaker, requiring the removal of the speaker’s jumpers.
Absolutely. By using only two channels, you get 100 watts per channel with the power supply operating under capacity. This setup optimizes channel separation and dynamics. Many users appreciate this versatility, allowing them to switch between stereo music listening and home theater sessions without compromise.
Matthias
Perfect for my three front speakers in my home theater. Neutral sound.
Comment from October 11, 2025 — Experience from December 10, 2023
Franck
From the very first listen, neutrality prevails.
I thought my Elipson Prestige 4i speakers would bring the amp to its knees, but that's not the case at all - on the contrary, the current reserve is phenomenal.
When switching to 5.1 on a NAD M15 preamp, the sound is soft during calm moments and becomes devastating as soon as the storm comes; you could almost do without a subwoofer, given how much energy it has.
For the price it's sold at, it's worth its weight in gold.
Comment from February 17, 2024 — Experience from February 03, 2024
Eric
I connected it to Fyne Audio speakers for the center and rear channels in a 3-way, 5-channel configuration.
The other two channels are free.
Comment from April 01, 2023 — Experience from March 25, 2023
