STAX SRM-400S Ex-Demonstration Semiconductor Driver Unit

This ex-demonstration STAX SRM-400S is sold with full manufacturer warranty, in excellent condition, and supplied with all original packaging and accessories.

For delivery enquiries, product information, or to book your personal audition, please telephone 01603 627010.

Premium Japanese-Engineered Electrostatic Headphone Amplifier

The STAX SRM-400S is a sophisticated semiconductor driver unit designed specifically for powering STAX electrostatic headphones. This meticulously engineered amplifier delivers exceptional signal purity and dynamic response, providing an immersive listening experience that reveals subtle musical details often lost in conventional headphone systems.

Advanced FET Implementation Technology

This ex-demonstration driver unit features cutting-edge semiconductor technology:

• Custom-made DUAL FET First Stage providing exceptionally low noise performance and precise signal handling
• FET-equipped Last Stage ensuring signal integrity throughout the amplification chain
• Strictly matched FET components individually tested and selected for optimal channel balance
• Zero coupling capacitors in the DC amplifier configuration, eliminating potential signal degradation
• Complete FET implementation across all amplification stages, following STAX’s flagship SRM-700S design philosophy

Refined Power Architecture

The SRM-400S driver unit delivers STAX’s characteristic performance improvements:

• Dedicated power transformer with separate high-voltage and low-voltage windings for improved efficiency
• Enhanced power utilisation yielding superior performance compared to the predecessor SRM-353X model
• Optimised voltage regulation ensuring stable power delivery under varying load conditions
• Environmentally conscious power design with reduced consumption without compromising sonic performance
• High-voltage output capability of 400Vrms (1kHz) for precise control of electrostatic elements

Comprehensive Connectivity Options

The STAX electrostatic headphone amplifier offers versatile integration options:

• Balanced XLR inputs for connection to premium source components with differential outputs
• RCA line-level inputs compatible with conventional single-ended audio equipment
• Mutual exclusion input switching preventing signal degradation through unwanted pathway interaction
• RCA parallel outputs allowing signal pass-through to additional components in your system

Refined Mechanical Design

The SRM-400S exemplifies STAX’s established design philosophy with:

• Hybrid chassis construction utilising non-magnetic aluminium for superior vibration rejection
• Enhanced structural rigidity compared to previous models, minimising microphonic effects
• Custom-made concentric dual volume control allowing precise adjustment of listening levels
• Compact form factor measuring just 195mm width by 102mm height, suitable for integration into space-conscious systems
• Premium finish quality reflecting STAX’s meticulous attention to aesthetic details

Technical Specifications

The STAX SRM-400S offers impressive performance metrics:

• Frequency response: DC – 90kHz (measured with SR-L500 MK2)
• Gain: 60dB
• Harmonic distortion: 0.01% or less (1kHz/100Vrms output)
• Input impedance: 50kΩ (RCA), 50kΩ x 2 (XLR)
• Bias voltage: DC 580V
• Power consumption: 30W
• Dimensions: 195 (W) x 102 (H) x 376 (D) mm (including protrusions)
• Weight: 3.4kg

Condition and Warranty Statement

This ex-demonstration STAX SRM-400S offers the opportunity to acquire a premium Japanese-engineered electrostatic headphone amplifier at a reduced cost compared to purchasing new, while maintaining full warranty protection. The unit has been meticulously maintained in our demonstration room and presents in excellent cosmetic and functional condition.

To arrange your personal demonstration of this ex-demonstration STAX driver unit, please contact us using the telephone number above.