IOTAVX PA40

The IOTAVX PA40 is a Class AB stereo power amplifier capable of delivering 2 × 300 watts into 4 ohms. Designed in the UK, it features a large toroidal transformer, supports mono bridging up to 600 watts, and boasts a robust build.

Meticulously engineered for standout performance

The PA40 is built on a carefully optimized Class AB topology, ensuring an ideal balance between energy efficiency and sound quality. This proven approach avoids the inherent shortcomings of Class D digital amplifiers while limiting the heat dissipation typical of Class A designs. Its rigid chassis, made from thick steel, minimizes parasitic vibrations that could degrade signal purity.

At the heart of the unit is a massive toroidal transformer, a crucial component that ensures stable and quiet power delivery. This centerpiece generates less electromagnetic noise than a conventional transformer, offers higher energy efficiency, and maintains a constant supply voltage even during the most demanding musical passages. The deliberately oversized transformer gives the PA40 substantial power reserves, enabling uncompressed reproduction of the most complex dynamics.

Carefully selected bipolar transistors, chosen for their exceptional linearity, operate in a push-pull configuration, with each device handling the positive and negative half-cycles of the signal in turn. This arrangement ensures each transistor operates in its optimal active region, minimizing crossover distortion while preserving musical integrity. The circuit also incorporates sophisticated bias networks with precision resistors and high-quality capacitors to guarantee a stable operating point over time.

Power versatility: from stereo to bridged mono

The PA40 demonstrates remarkable flexibility in power management. In standard stereo configuration, it delivers 2 × 150 watts into 8 ohms and climbs to 2 × 300 watts into 4 ohms. This substantial power reserve ensures effortless reproduction of dense musical passages, maintaining crystal-clear clarity even at high volume levels.

The PA40’s true technical prowess lies in its ability to switch to bridged mode. In this mono configuration, the amplifier channels all its power into a single output, delivering 300 watts into 8 ohms or an impressive 600 watts into 4 ohms. This feature opens exciting possibilities for advanced audio setups: use as an ultra-powerful monoblock in a reference hi-fi system, driving a center channel in a hybrid home theater configuration, or powering particularly demanding speakers.

Switching between modes is handled by a dedicated selector on the rear panel, allowing quick reconfiguration as needed. This dual personality gives the PA40 rare versatility at its price point, making it equally suited to refined stereo listening and demanding professional applications.

Comprehensive connectivity and seamless system integration

The PA40’s versatility is reflected in its diverse connection options. The amplifier offers both unbalanced RCA and balanced XLR inputs, ensuring optimal compatibility with any audio source. Balanced XLR connections significantly reduce background noise and interference over long cable runs—a valuable advantage in complex installations.

The PA40 can drive two pairs of speakers simultaneously via high-quality A and B binding posts. This function is invaluable for effectively filling large spaces or quickly comparing different speaker models. The terminals accept banana plugs, spades, or bare wire, offering maximum flexibility in speaker cable choice.

A recording output completes the package, allowing the amplified signal to be captured for archiving or distribution. Standby power consumption below 0.5 W reflects an environmentally conscious design with no compromise on performance. The auto-switching 115/230 VAC power supply ensures worldwide compatibility, making it easy to use in different countries without modification.

IOTAVX: a distinctive British trajectory

IOTAVX embodies an innovative approach to the high-end audio market. Founded in 2015 in Middlesbrough by audio enthusiast Ian Vermeulen, who brought extensive industry experience, the British brand was born of a clear vision: deliver exceptional performance at highly competitive prices through a direct-to-consumer model.

The company initially operated under the Nakamichi brand before Vermeulen made the bold decision to establish his own identity. The first product developed under the IOTAVX name was the AVXP1 seven-channel amplifier. Despite modest beginnings with only five units sold in the first year, enthusiastic word of mouth from satisfied users on specialist forums quickly propelled the brand.

In 2017, the addition of German audio experts Jens Hörmann and Berthold Daubner marked a decisive turning point. Their combined expertise—totaling more than 60 years in the AV industry—helped optimize existing technologies and introduce innovative approaches. This successful collaboration culminated in the full transfer of the company to Hörmann and Daubner in 2023, with Vermeulen entrusting them to carry his vision forward, confident they would maintain the established standards of excellence.

Technical Specifications

Type and Design

• Stereo power amplifier (Class AB)
• Robust construction
  • Rigid chassis for enhanced longevity
  • Toroidal transformer for stable, low-noise power

Output Power

• Stereo mode
  • 2 x 150 W into 8 Ω
  • 2 x 300 W into 4 Ω
• Bridged mode (mono)
  • 1 x 300 W into 8 Ω
  • 1 x 600 W into 4 Ω

Audio Performance

• Total harmonic distortion + noise (THD+N): < 0.003% (100 W, 1 kHz)
• Signal-to-noise ratio (SNR): > 110 dB (100 W, A-weighted)
• Frequency response: 20 Hz–80 kHz (±0.5 dB)

Connectivity

• Inputs: 1 x RCA (unbalanced), 2 x XLR (balanced)
• Outputs: Speakers A, B, A+B, 1 x recording output
• Ability to connect two pairs of speakers

Power and Consumption

• Power supply: 115 VAC or 230 VAC auto-switching, 50 / 60 Hz
• Standby power consumption: < 0.5 W

Dimensions and Weight

• Dimensions (W x H x D): 435 x 133 x 315 mm (height including feet)
• Weight: 9.6 kg

Packaging and Warranty

• Packaging
  • Weight: 11.5 kg
  • Dimensions: 52 x 42 x 23 cm
• Warranty: 2 years