Наушники — Stax SR-003MK2

The SR-003 MK2 is a canal-type in-ear earspeaker from Stax, the Japanese company that builds electrostatic headphones and the driver units that power them. It uses a push-pull electrostatic element rather than a dynamic or balanced armature driver, and it has been in production since 2012. Its compact form sits in the ear and does not cover it, and as with all Stax models it cannot run from a normal headphone socket and needs a dedicated energiser.

Key specs that matter

Stax gives a response of 20 Hz to 20 kHz within plus or minus 4 dB. Sensitivity is 110 dB at an input of 100 V RMS at 1 kHz, and the static capacity is 44 pF including the attached cord. The bias voltage required is 550 V to 580 V. Total weight is 38 g with the cable, while the main part alone weighs 12 g. Each earpiece is 28 mm in diameter.

Engineering and use context

Compared with earlier versions, the diaphragm film is about 15 percent thinner and lighter. The earpieces sit in the ear canal on silicone rubber tips, supplied in L, M and S sizes, with the M size fitted at the factory. An overhead arc weighing 15 g helps hold the cable and earpieces in place. The cable is a 6-core parallel design with a total length of 1.5 m, ending in a STAX 5-pin connector for Pro bias. That plug means the SR-003 MK2 can be connected to any driver unit that has a Pro bias output socket, and it cannot be used with older Normal bias drivers.

Pairing

For use away from a hifi rack, the SRM-D10 II is the portable driver unit in the current Stax range. It weighs 475 g, measures 75 x 32 x 141 mm, takes USB-C digital and 3.5 mm analogue inputs and supplies the Pro bias voltage, with a stated battery life of 4.5 hours on analogue input or 3.5 hours on digital input. At home the SRM-D50 adds a converter with USB, optical and coaxial sockets and supplies 59 dB of gain with up to 400 V RMS of output, while analogue drivers such as the SRM-500T serve systems that already include a separate DAC. The SRM-500T pairs a FET input with a 6FQ7/6CG7 tube output stage, offers RCA and XLR inputs and 60 dB of gain, and delivers up to 300 V RMS from a 3.4 kg case.

Alternatives

The Stax SR-L500 MK2 is a headband earspeaker with an oval push-pull element, a rear open-air enclosure, a frequency response of 7 Hz to 41,000 Hz and a weight of 479 g including its cable.