STAX SRM-400S Solid State Driver

$2,500.00

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Stax

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Japan

STAX SRM-400S Solid State Driver

Name: STAX SRM-400S Solid State Driver
Brand: Stax
SKU: SE-SRM400s
Price: 2500.0 AUD
Availability: InStock

SKU: SE-SRM400s

$2,500.00

Includes GST. 🚚 Free shipping on orders over $100 Australia wide at checkout.

High-voltage, low-noise solid-state circuitry provides precise bias and drive for electrostatic headphones. Fully balanced discrete design ensures low distortion and strong channel separation. Stable output preserves speed, detail, and spatial realism with transparent amplification.

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Colour:Silver

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Description

Middle-class semiconductor driver unit is renewed.
New DC amplifier which FET are installed in all stages.

STAX introduces a new semiconductor driver unit SRM-400S, the successor model of SRM-353X. STAX custom-made low noise DUAL FET is installed on First Stage. And FET is also installed on Last Stage. The characteristics of right FET and left FET are measured strictly. Selected FET are installed as well as SRM-700S. SRM-400S succeeds to the design and the manufacturing method of the high end model SRM-700S, the amplifier which FET are installed in all stages.

In addition to the conventional power transformer for the high voltage circuit, the newly designed power transformer with the winding for the low voltage circuit is installed in SRM-400S. The low voltage winding enables to improve the power efficiency and achieve further power saving and better sound quality than the conventional driver units such as SRM-353X.

The new chassis which is more rigid than the conventional model is installed. The chassis has a hybrid structure using a lot of non-magnetic aluminum and further reduces the effect of the environmental noise factors such as vibrations. The inputs are RCA and XLR, the mutual exclusion inputs. The custom made concentric dual volume knob which is common to STAX products and RCA PARALLEL OUT functions are installed same as the conventional driver units. All electric components are strictly selected considering the environment. Also the sound quality and the performance is improved. The complete DC amplifier configuration that the signal circuit includes no coupling condensers is one of the biggest traditional features.

SRM-400S takes over the high resolution sound which is unique to the semiconductor circuit and dynamic low range sound reproduction. Simultaneously, the good sound balance is further pursued than SRM-353X. From the low range to the high range, the sound of each range is well harmonized. Not only for the combination with the advanced lambda series, SRM-400S is also ideal for the upgrading from the entry level SRS-3100. This is the promising new model which covers from beginners to intermediates among the renewed driver unit lineup.

Rear Panel

Tech Specs

Type

All-stage FET configuration DC amplification driver unit

Frequency response

DC – 90kHz (with one SR-L500 MK2)

Gain

60dB

Harmonic distortion

0.01% or less (1kHz/100Vrms output)

Input impedance

50kΩ (RCA), 50kΩx 2 (XLR)

Maximum output voltage

400Vrms (1kHz)

Bias voltage

DC 580V

Operating temperature / humidity

0 to 35 degrees C / less than 90% (non condensing)

Input terminal

RCA x 1, XLR x 1(mutual exclusion input)
Output

RCA parallel output terminal

Power consumption

30W

Dimension

195 (W) x 102 (H) x 376 (D) mm (maximum protruding portion included)

Weight

3.4kg

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Warranty Information

1 Year Warranty

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Why Choose Stax

STAX is one of the most respected and historic names in personal audio, renowned worldwide for its electrostatic headphone technology and uncompromising approach to sonic purity. Manufactured in Japan, STAX products are designed for listeners seeking an exceptionally open, detailed, and transparent presentation that conventional headphone designs often struggle to achieve.

For many enthusiasts, hearing a properly matched STAX system for the first time is a genuinely memorable experience. The speed, delicacy, and effortless clarity of electrostatic headphones create a presentation that feels incredibly immediate and lifelike, revealing fine detail and subtle textures with remarkable ease. Vocals, strings, piano, and acoustic recordings in particular benefit from the spaciousness and realism that STAX systems are capable of delivering.

At HeyNow Hi-Fi, STAX appeals to customers who want to move beyond traditional headphone listening and experience something genuinely unique within high-end personal audio. While electrostatic systems require dedicated energisers and careful system matching, the reward is a level of refinement and transparency that continues to make STAX one of the true reference brands in the headphone world.

Signature Design and Sound

STAX products are built around the company’s long-standing electrostatic driver technology, which uses an ultra-light diaphragm suspended between electrically charged plates to achieve extraordinary speed and precision. This design allows STAX headphones to respond to musical signals with exceptional accuracy and minimal distortion.

Sonically, STAX systems are renowned for their openness, air, and micro-detail retrieval. The presentation feels highly spacious and unconstrained, with outstanding separation and a remarkable ability to reveal subtle nuances within recordings. Unlike some conventional dynamic or planar headphones, STAX products often create a sense of effortlessness and transparency that feels closer to listening to high-end loudspeakers in a well-treated room.

Importantly, despite their extraordinary detail retrieval, STAX systems avoid sounding aggressive or overly sharp when correctly partnered, instead delivering a refined and highly natural presentation that encourages deep listening sessions.

Stax Product Range

The STAX range includes electrostatic headphones, dedicated driver units (energisers), and complete headphone systems designed for both enthusiast and reference-level listening. Models including the SR-L700 MKII, SR-007, and flagship SR-X9000 have become highly regarded amongst serious headphone enthusiasts seeking the highest levels of resolution and realism.

STAX driver units and energisers are carefully matched to their headphones, allowing customers to build complete systems tailored to different performance levels and listening preferences. Whether entering the world of electrostatic headphones for the first time or pursuing a true reference personal audio system, STAX remains one of the most iconic and technically unique brands in high-end headphone listening.

Explore the STAX range:

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