STAX SRM-313

Second-hand. In good conditions. Shows slight signs of wear. Comes with headphones, accessories, and original packaging.

The SRM-313 is a driver unit designed to deliver natural and detailed sound quality. Its low-impedance output stage has been completely redesigned with a state-of-the-art follower circuit, which, combined with an improved power supply, produces vivid, expansive, and dynamic sound.

This amplifier can drive STAX electrostatic headphones without any loss of sound quality, thanks to the absence of transformers between the amplifier and the headphones. Its simplified two-stage circuit combines a low-noise dual FET in the first stage with a high dielectric strength transistor in the second stage, ensuring natural tone reproduction rich in sound information.

All circuitry, from input to output, is direct current and does not use coupling capacitors, contributing to signal purity.

Following STAX’s design concept, the device uses non-magnetic components as much as possible, including the chassis, to minimize interference. Long-life electronic parts are also selected to maintain sound quality over time.

The SRM-313 is compatible with all STAX headphones, including Pro bias, Normal, and electret types, and features parallel input and output terminals for right and left channels, facilitating connection with other audio devices.

Technical specifications:

• Type: Solid-State Class-A DC direct Driver Unit for Earspeakers
• Maximum Output Voltage: 350V r.m.s.
• Harmonic Distortion: less than 0.01% at 1kHz
• Input Sensitivity: 100mV / 100V Output
• Input Impedance: 50k ohms
• Frequency Range: DC ~ 48,000Hz
• Gain: 60dB
• Bias Voltage: PRO 580V × 2
• Power Consumption: 29W
• Operating AC Voltage: 117/220/240V, 50/60Hz
• Operating Temperature: 0 ~ 40 °C
• Dimensions: 150 (W) × 103 (H) × 370 (D) mm
• Weight: 2.9 kg