5m / 16.4ft standard extension cord, works for all Stax pro-bias (5-pin) compatible headphones.
About Stax Headphones
Stax produce exclusively electrostatic headphones, or “earspeakers” as they call them, in Japan, since 1938. Stax chose the electrostatic technology for its ability to produce transparent sound, and low weight for comfort/ergonomics, both due to the driver design not employing fixed magnets and moving coils, as opposed to other common headphone driver designs. The minimal weight of the driver ensures a very quick response to the signal, creating a more faithful sound reproduction.
The electrostatic driver creates sound when it is powered by static charge (bias voltage), which reacts to a high voltage signal field created around the driver element by the stators. For this reason, all electrostatic headphones require special amplification to supply the high voltage (DC) bias, and high voltage (AC) audio signal. In the case of modern Stax headphones, that DC bias is 580V. Stax manufactures a number of dedicated amplifiers for their headphones, ranging from a relatively small portable model, SRM-D10, to their flagship SRM-T8000.