Stax SRM-500T Valve Energiser

The Stax SRM-500T Valve Energiser is a new model introduced in 2020 to replace the previous STAX SRM-006tS driver unit.  The SRM-500T features a pair of 6FQ7/6CG7 vacuum tubes on the output stage, driven by low noise dual FET. STAX Audio prides itself in offering the best possible performance and great value electrostatic driver.

The SRM-500T features a new power transformer with windings for the low voltage circuit. The low voltage winding improves power efficiency which in turn achieves improved sound reproduction than conventional vacuum tube output driver units.

A more rigid chassis is installed using a hybrid structure of non-magnetic aluminium, which reduces the effect of vibrations and environmental noise factors.

RCA and XLR inputs sockets are provided. The custom-made concentric dual volume knob is common to STAX products and RCA PARALLEL OUT functions are installed as per conventional driver units. All electric components are strictly selected considering the environment, sound quality and overall performance is improved.

The DC amplifier configuration includes no-coupling condensers, one of the biggest traditional features. Delivering clear and highly transparent sound – a feature of this vacuum tube circuit – in addition to a warm, wide texture, and improved thickness of the low-mid range. This driver unit is the new choice for the advanced lambda series earspeakers (SR-L300/SR-L500 MK2/SR-L700 MK2).

Technical Specifications:

Type: FET + vacuum tube output hybrid DC amplifier configuration / driver unit
Vacuum tube : 6FQ7 / 6CG7
Frequency response: DC to 90kHz (when using one SR-L500 MK2)
Gain: 60dB
Harmonic distortion rate: 0.01% or less (at 1kHz / 100V r.m.s. output)
Input impedance: 50kΩ (RCA), 50kΩ x 2 (XLR)
Maximum output voltage: 300V RMS (1kHz)
Bias voltage: DC 580V
Operating ambient temperature / humidity: 0 to 35 ° C / 90% or less (however, no condensation)
Input: RCA x 1 XLR x 1
Output: RCA out
Power consumption: 38W
Dimensions: 195W x 102H x 376Dmm (including protrusions such as knobs)
Weight: 3.4kg
Country of origin: Japan