About The STAX SRM-400S Headphone Amplifier
STAX proudly unveils the SRM-400S, a state-of-the-art semiconductor driver unit that builds upon the legacy of the acclaimed SRM-353X. The SRM-400S features custom-made, low-noise DUAL FETs on both the First and Last Stages, meticulously measured and selected for optimal performance, just like the high-end SRM-700S. By incorporating FETs in all stages, the SRM-400S achieves an unprecedented level of audio fidelity, setting a new standard in headphone amplification.
The SRM-400S introduces a revolutionary power transformer that significantly enhances power efficiency and sound quality. Alongside the traditional high-voltage circuit transformer, a newly designed low-voltage circuit transformer ensures improved performance and reduced power consumption. This innovation allows the SRM-400S to deliver superior audio output compared to its predecessors, such as the SRM-353X, making it an exceptional choice for discerning audiophiles.
A more rigid chassis design distinguishes the SRM-400S from previous models, utilizing a hybrid structure of non-magnetic aluminium to minimize environmental noise and vibrations. This robust construction, coupled with RCA and XLR inputs and a custom-made concentric dual volume knob, underscores STAX's commitment to precision and quality. Additionally, the SRM-400S retains essential features like the RCA Parallel Out and a complete DC amplifier configuration, ensuring a pure signal path free from coupling condensers.
The SRM-400S excels in delivering high-resolution sound and dynamic low-range reproduction, achieving a balanced audio experience. Its seamless integration with advanced lambda series headphones and suitability for upgrading from entry-level models like the SRS-3100 make it a versatile choice for both beginners and intermediate users. With the SRM-400S, STAX continues to lead the way in audio innovation, offering a promising new model that caters to a wide range of audiophiles.
Why Electrostatic Headphones?
Electrostatic headphones operate on a different principle than conventional "dynamic" or "moving coil" designs. In a conventional headphones there is a coil of wire inside a magnet, generally glued to a stiff cone or dome that's held in place with a springy suspension. This makes in more difficult to re-create detail in playback due to mass. Or to put simply there are more heavy moving parts.
Pioneered by STAX in 1959 – an electrostatic design works by placing a static (non-moving) electric charge on a film that floats between two perforated metal plates. When audio voltages are applied across the plates, static cling and repulsion causes the entire film to move by itself. This film is so thin, it effectively weighs less than the air around it, and has no resonances or energy storage which leads to distortion inherent in moving coil speakers.
These factors are one of many reasons why STAX electrostatic Headphones sound so much better than conventional designs. During play back the listener is experiencing minimal interference from the headphone speaker itself, in turn bringing you that much closer to the original artist's performance.
Our Take
The STAX SRM-400S is a state-of-the-art semiconductor driver unit building upon the legacy of the acclaimed SRM-353X. Featuring custom-made, low-noise DUAL FETs on both the First and Last Stages, meticulously selected for optimal performance, the SRM-400S achieves an unprecedented level of audio fidelity. It introduces a revolutionary power transformer that enhances efficiency and sound quality, paired with a more rigid chassis design to minimize noise and vibrations. With RCA and XLR inputs, a custom concentric dual volume knob, and a complete DC amplifier configuration, the SRM-400S excels in high-resolution sound and dynamic low-range reproduction, making it an exceptional choice for both beginners and discerning audiophiles.
Main Features & Specifications
- Design: Headphone Amplifier/Energiser for STAX Electrostatic Headphones
- Recommended STAX Headphones: SR-X1, SR-L300, SR-L500 MK2, SR-L700 MK2
- Frequency Response: DC to 90,000Hz/+0, -3dB
- Harmonic Distortion: 0.01% or less/1kHz 100V
- Amplification: 60dB
- Maximum Output Voltage: 400V/1kHz
- Input Impedance: 50k Ω
- Input Terminals: Stereo RCA Inputs x 1, Stereo XLR Inputs x 1
- Output Terminals: Parallel RCA Outputs x 1
- Bias Voltage: 580V DC
- Power Consumption: 30W
- Dimensions (WxHxD): 195 x 102 x 376mm
- Weight: 3.4 kg
- Manufacturer's Warranty: 1 Year
Note: Features & Specifications Subject To Change Without Notice. E&OE.