PS Audio Begins Shipping PMG Signature S400 and S200 Power Amplifiers

PS Audio has introduced two stereo power amplifiers, the PMG Signature Series S400 and S200. The components were designed by Darren Myers with the participation of engineer Bob Stadherr and are intended for use in high-end two-channel audio systems. Both models join the PMG Signature family, which was launched in 2025 to mark the American company’s 50th anniversary.

The main difference between the new models lies in their output power. The flagship PS Audio S400 is capable of delivering 400 watts per channel into a 4-ohm load. Under the same conditions, the smaller S200 produces 200 watts per channel. Both amplifiers use identically sized enclosures and are designed to work with a wide range of loudspeakers.

At lower output levels, both models operate in pure Class A. The S400 remains in this mode for its first 5 watts, while the S200 operates in Class A for its first 10 watts. According to PS Audio, this approach should provide more natural and detailed reproduction at moderate listening levels, which are commonly used during everyday music playback.

The amplifiers employ an active power-supply architecture instead of a conventional design based on a standard mains transformer. According to the manufacturer, the new architecture reduces noise in the power-supply circuitry and enables the amplifiers to deliver the required current more quickly during dynamic peaks and sudden changes in the musical signal.

The circuitry of the PMG Signature S400 and S200 power amplifiers uses extremely low levels of negative feedback. Their operating bandwidth exceeds 500 kHz, while the specified slew rate is more than 200 V/μs. The internal enclosure layout has also been designed to minimise interference between the left and right channels.

Balanced and unbalanced inputs are provided for source connections. Each amplifier is equipped with two pairs of loudspeaker terminals, allowing speakers to be connected in a bi-wiring configuration. Separate outputs for left and right subwoofers are also included, along with a 12-volt trigger for easier integration into home cinema systems and complex custom installations.

The PS Audio PMG Signature S400 and S200 power amplifiers are available in black and silver finishes. Both models measure 44.45 × 22.23 × 42.55 cm. The S400 weighs 25.95 kg, while the S200 weighs 25.49 kg. In the United States, the flagship model carries a recommended retail price of US$9,999, while the smaller amplifier is priced at US$7,999.