The Stax SRM-1 Pro is an electrostatic headphone amplifier designed to provide clean power to electrostatic headphones, particularly compatible with Stax Lambda series models. It features a dual output configuration with 'Pro' and 'Normal' sockets, catering to different headphone specifications. The amplifier is recognized for its uncolored sound signature, delivering a neutral and transparent listening experience. It operates in pure class-A and is DC-coupled, ensuring distortion-free audio across the spectrum. Certain models come equipped with a voltage switch, allowing users to adapt the unit for different power requirements. The build quality of the SRM-1 Pro is robust, featuring discrete components and a user-serviceable design. Common modifications include rewiring for balanced operation and replacing aging capacitors in the power section. Users have reported that the amp can efficiently drive high-impedance electrostatic headphones like the Stax Omega series, making it a valuable option for those not ready to invest in higher-end models such as the SRM-7x7 or KGSS/Exstata. With adequate power reserves, the SRM-1 Pro is capable of reproducing clear and detailed audio with significant headroom, minimizing the risk of clipping even at elevated volumes. Dimensions and weight are compact, providing a substantial yet manageable presence on a desktop setup. Overall, when refurbished and properly maintained, the Stax SRM-1 Pro offers an exceptional performance-to-value ratio for electrostatic headphone enthusiasts.
