About The STAX SRM-D50 Electrostatic Headphone Amplifier/DAC
The SRM-D50 is a high-performance electrostatic driver and digital-to-analogue converter, inspired by the battery-powered SRM-D10. With an elegant all-in-one design, the D50 creates a simple solution for any music lovers to experience the legendary sound of STAX Earspeakers.
Exquisitely Built: The entire chassis is made from Aluminium reducing the effects of magnetic interference. The SRM-D50 features a one piece wrap round lid. This lid goes through several processes to achieve a smooth velvet feel. The STAX logo is engraved into the top of the lid.
High-Resolution Playback: On the digital side, the SRM-D50 uses an XMOS USB interface with support for DSD 5.6MHz signal playback and PCM audio with up to 384KHz sample rate.
High End DAC: On the digital conversion side, STAX chose to use the ESS ES9018 DAC. Renowned for its superb sound quality, the ES9018 is then fed to a 'TI OPA1642' ultra-low distortion op amp to ensure the delicate bitstream remains unaltered.
Multiple Input Selection: The SRM-D50 features both analogue & digital inputs. The three digital inputs are USB, Coaxial and Optical, while the analogue input is via RCA.
Traditional STAX Amplifier Circuit: The SRM-D50 features an original low noise dual FET first stage, connecting to a direct coupled Class A DC amplifier, which features no coupling capacitors. This allows for the smallest nuances in the music to be reproduced. Improvements to the emitter follower at the output stage results in extended dynamic range, natural tonality and inner detail. Carefully selected components have been chosen not just for their long life and reliability but equally for their tonal quality and unmatched performance.
VU Meter: The SRM-D50 is fitted with an illuminated VU Meter to monitor input level. If connected to a variable output component the meter can be used to monitor input level and in turn avoid input clipping.
The SRM-D50 Is A New Generation Electrostatic Energiser: It allows multiple source selection, including high resolution USB audio interface, coaxial S/PDIF and optical connection. This is coupled with a traditional analogue connection. Overall the SRM-D50 is a combination of modern aesthetic design, high quality digital signal processing and the values of traditional STAX craftsmanship.
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
From the moment we fired up the SRM-D50 it just sounded right. It didn't even matter which STAX earspeakers were employed, they all sound wonderful of course, because it drove all of them superbly and had a solidness in the lower midrange and bass that made the STAX earspeakers sound punchy and dynamic which is not always the case with electrostatics. Add to this the wonderful flexibility, with one analogue and three digital inputs, and you have a complete music system for your desk or den that you can listen to and enjoy for hours at a time. Come and have a listen to the STAX range in our comfortable showrooms in Ringwood, Melbourne.
Main Features & Specifications
- Design: Compact Electrostatic PRO Series Headphone Amplifier/DAC for STAX Electrostatic Earspeakers
- Use with these STAX Earspeakers: STAX SR-L300, STAX SR-L500 Mk2, STAX SR-L700 MK2
- ESS ES9018 DAC coupled with 'TI OPA1642' ultra-low distortion op amp to achieve bit correct signal representation
- XMOS USB interface supports DSD128 playback and PCM stream with up to 384KHz sample rate
- This high-performance DAC can be connected to a MAC / PC or a variety of digital audio sources
- Multiple digital inputs include USB-B, S/PDIF on RCA and Optical
- Analogue sources can also be connected via RCA
- Amplifier circuitry based on discrete components as used in classical STAX amplifier products
- A useful illuminated VU meter is cleverly housed on the front panel
- Carefully selected internal high quality components
- Full Aluminium housing with multiple surface processing to achieve a velvet feel
- Standard STAX 5-Pin PRO connector for all current STAX headphones
- Frequency Response: DC-40kHz (0,-3dB)
- Rated Input Level: 130mV rms
- Maximum Input Level: 30V/ RCA, at minimum volume
- Maximum Output Voltage: 400V rms (1130Vp-p)
- Gain: 59dB
- Harmonic Distortion: 0.025% or less/1kHz-10kHz /When use with SR-L series
- Input Impedance: 20kΩ (RCA)
- Bias Voltage: DC580V
- Power Consumption: 35W
- Operating Temperature: 0 to 35 degrees C (less than 90% humidity, non-condensing)
- Dimension (WxHxD): 192 x 67 x 268mm
- Weight: 4.5kg
- Manufacturer's Warranty: 1 Year
Note: Features & Specifications Subject To Change Without Notice. E&OE.