SRM-400S Headphone Amplifier

The Stax SRM-400S Headphone Amplifier is a meticulously engineered solid-state “energizer” from Stax, specifically crafted to unleash the full potential of their electrostatic earspeakers. As the successor to the acclaimed SRM-353X, the SRM-400S elevates performance with a pure Class A solid-state DC amplification design, incorporating high-quality non-magnetic FETs for exceptional linearity and detail. A significant upgrade lies in its newly designed power transformer, featuring independent windings for both low and high-voltage circuits, which dramatically enhances efficiency, reduces noise, and refines the overall sound quality. Housed in a robust, hybrid aluminum chassis, the amplifier effectively suppresses external vibrations and interference. It offers both RCA and XLR (balanced) inputs for versatile connectivity and provides two 5-pin Pro bias (580V DC) outputs, allowing two pairs of Stax headphones to be driven simultaneously. Delivering a wide DC-90kHz frequency response and ultra-low distortion, the SRM-400S offers a transparent, dynamic, and exceptionally clean sound, making it an ideal choice for discerning audiophiles seeking precise control and fidelity for their Stax electrostatic system.