Stax SRM-400S Headphone Amplifier

This amplifier is specifically engineered for Stax electrostatic earspeakers. It provides the necessary 580V DC bias voltage required to power these specialized headphones, so it will not work with standard dynamic or planar magnetic headphones.

Yes, the SRM-400S includes an RCA parallel output function, which allows you to pass the signal through to an external power amplifier or active speakers. It effectively acts as a high-quality preamp in your signal chain.

As a semiconductor-based driver, the SRM-400S offers a more precise, high-resolution sound profile compared to the warmer, more colored presentation of tube amplifiers. It excels in delivering tight, dynamic low-range reproduction and exceptional clarity across the frequency spectrum.

Yes, it features both XLR and RCA inputs. You can connect a balanced source via the XLR input to take advantage of the fully balanced signal path, though note that the inputs are mutually exclusive and cannot be used simultaneously.

By removing coupling capacitors from the signal path, the amplifier avoids the phase shifts and signal degradation often associated with these components. This results in a cleaner, more transparent sound that maintains the integrity of the original recording.

The custom concentric dual volume knob allows you to adjust the left and right channels independently, which is useful for balancing the stereo image if your hearing or source components are slightly asymmetrical. If you prefer standard operation, you can simply turn both sections together as one.