STAX SRM-500T

SRM-500T: The New Generation of Mid-Range Vacuum Tube Driver

With the SRM-500T, STAX introduces the successor to the popular SRM-006tS, marking a complete overhaul of the model. The new vacuum tube output driver uses STAX’s proprietary low-noise DUAL FET in the first stage and a vacuum tube in the output stage. STAX continues to adhere to its tried-and-true circuit design optimized for tube drivers while enhancing the energy efficiency of the driver, resulting in a significant sound improvement.

An additionally developed transformer, specially wound for the low-voltage range, complements the conventional transformer for the high-voltage circuit. This additional low-voltage winding not only contributes to energy savings but also enhances sound quality compared to its predecessor, the SRM-006tS.

The SRM-500T comes housed in a newly designed, highly stable hybrid structure made from non-magnetic aluminum that effectively reduces the influence of ambient noise and vibrations. The inputs feature RCA and XLR connectors with mutual exclusion. Like other STAX drivers, the SRM-500T includes a custom-made concentric double volume control and RCA-PARALLEL-OUT functionality. All electrical components have been carefully chosen to ensure both top-tier sound quality and environmental sustainability. The fully DC-coupled amplifier design, which avoids coupling capacitors in the signal paths, is one of the traditional hallmarks of this series.

The SRM-500T preserves the clear, transparent sound character of tube circuitry along with a warm, broad sound texture. The low and mid-range frequencies have been acoustically enhanced and further refined, making it the ideal driver for the advanced Lambda models (SR-L300, SR-L500 MK2, SR-L700 MK2).

Technical Specifications of the SRM-500T

• Type: FET input + vacuum tube output hybrid DC amplifier unit
• Vacuum Tube: 6FQ7/6CG7
• Frequency Response: DC – 90kHz (with an SR-L500 MK2)
• Gain: 60 dB
• Harmonic Distortion: ≤ 0.01% (at 1kHz/100Vrms output)
• Input Impedance: 50 kΩ (RCA), 50 kΩ x 2 (XLR)
• Maximum Output Voltage: 300Vrms (1kHz)
• Bias Voltage: DC 580V
• Operating Temperature/Humidity: 0 to 35 °C, below 90% humidity (non-condensing)
• Input Terminals: RCA x 1, XLR x 1 (mutually exclusive)
• Output: RCA parallel output terminal
• Power Consumption: 38 W
• Dimensions: 195 mm (W) x 102 mm (H) x 376 mm (D) (including maximum protruding parts)
• Weight: 3.4 kg

The SRM-500T is an exceptional choice for audiophiles seeking a powerful and refined sound experience, offering a blend of advanced tube technology and modern enhancements for optimum performance.