HPA-S400ET review by Michael Andrew

Read Michael Andrew's review of the Audiophonics Workshop HPA-S400ET power amplifier. The Audiophonics HPA-S400ET is a Class D power amplifier based on the use of two Purifi 1ET400 modules, enabling it to deliver 2x 400W power at 4 ohms. This amplifier is designed with a dual-mono structure, with one Purifi amplifier module per channel, to process the signal in the best possible way. In addition to its considerable power reserve, the HPA-S400ET demonstrates exemplary linearity for clear, precise and rich sound reproduction. This power amplifier will enable you to drive demanding speakers, whether for large room PA or professional studio applications. The HPA-S400ET is powered by a high-efficiency, low-noise HYPEX SMPS1200A400 switch-mode power supply capable of delivering a rated power of 1200W. In addition, an interface card allows 3 different jumper-adjustable gain settings to be configured, adapting the amplifier's use to various situations. The whole unit is housed in a sturdy aluminum case with vents and heat sinks for optimum heat dissipation, as well as simple, elegant curves. Last but not least, you'll find the usual connectivity on the back of the case, with RCA input, balanced XLR input and output on speaker terminals, complemented by two 5-12V Trigger connectors.

"I've never experienced a Class D amplifier like this. It takes a lot of energy to drive Infinities speakers, and this amplifier had no problem doing it. The midrange is clear enough to bring out the vocals, the bass is fantastic and the highs are simply perfect! The HPA-S400ET offers a sound reproduction with a natural warmth superior to some class A/B amplifiers, which is quite surprising for a class D!"