Stax SRM-700S: High-end driver headphone amplifier

Following the flagship SRM-T8000 driver-amplifier , Stax announced the start of production of two highly efficient, new-generation high-end driver-amplifiers: the hybrid (i.e., with tube output) SRM-700T and the all-semiconductor SRM-700S

. You can’t surprise anyone with a driver-amplifier using headphone tubes, be they dynamic or electrostatic. Stax nevertheless continues to develop and release new models that pique our interest. In the new driver-amplifier SRM-700S, STAX developers, in addition to traditional solutions, for the first time used a lot of innovations that had not previously been used in the design of proprietary equipment. For example, if at the input of the device they installed the same dual operational amplifiers based on field-effect transistors, manufactured to order by the company, with an exceptionally low noise level and high gain with imperceptible distortion, then in the output stage, for the first time in the history of the company, circuit solutions based on field-effect transistors with control PN junction (J-FET).

The output stage using J-FET technology is characterized by exceptionally low noise levels, and the subsequent use of a repeater with high output current values ​​allows the full potential of connected headphones, excuse me, ear speakers, to be realized. This solution makes it possible to easily control a musical signal with a large content of high-frequency components. The driver amplifier excels at highly accurate reproduction of even the fastest and most subtle details and nuances of your favorite music. The legs of the device are made of aluminum, and the supporting “heel” is made of a special vibration-resistant material with a high coefficient of friction, as a result of which the user does not have to hold the driver-amplifier when connecting wires. Design features: DC driver-amplifier circuit design exclusively based on field-effect transistors in both the input and output stages.

Stax SRM-700S Specifications

Frequency response: DC – 100 kHz (with one pair of Stax SR-009S headphones connected ).
Gain: 60 dB.
Harmonic distortion: 0.01% or less (at 1 kHz/100 V RMS output).
Input Impedance: 50 kΩ (RCA), 50 kΩ x 2 (XLR) Maximum Output Voltage: 450 V RMS (at 1 kHz)
Offset Voltage (Headphones Only): 580 V
Operating Temperature/Humidity: 0 to 35 degrees C/ less than 90% (no condensation)
Input Connectors: RCA x 1 pair, XLR x 1 pair.
Output: RCA parallel output connectors
Power consumption: 46 W
Dimensions: 240 (W) x 103 (H) x 393 (D) mm (at maximum projection)
Weight: 6.3 kg