Koss ESP/950 electrostatic stereophones Specifications

Sidebar 1: Specifications

Description: Electrostatic headphones with separate energizer unit. Frequency range: 8Hz–35kHz (no tolerance given). Sensitivity: 104dB at 100Vrms differential input at 1kHz. Diaphragm thickness: 1.5;um. E/90 Energizer/Amplifier. Frequency response: 1.6Hz–50kHz ±3dB at 100Vrms differential output. Input impedance: 100k ohms. Input level: 1Vrms for full output. THD+noise: 0.001% at 1kHz and 100Vrms differential output. Voltage amplification: 60dB. Channel separation: 80dB at 1kHz, 100Vrms differential output. Audio output voltage: 600Vrms differential, 2300Vrms push-pull with soft limiting. S/N ratio: 100dB at 100Vrms output. Bias voltage: 600V DC.
Dimensions: Energizer, 2.6" (65mm) H by 4.33" (110mm) W by 4.33" (110mm) D. Weight: 17oz. Headphones, Weight: 12.45oz.
Price: headphones and energizer/amplifier, $2000 (1992); $999.99 (2010). Approximate number of dealers (for ESP/950): 5
.Manufacturer: Koss Corporation, 4129 N. Port Washington Ave., Milwaukee, WI 53212. Tel: (414) 964-5000. Fax: (414) 964-8615. Web: koss.com.

Koss Corporation
4129 N. Port Washington Ave.
Milwaukee, WI 53212
(414) 964-5000

ndimoff's picture

Another great news is that the electrostatic transducers of the Koss'es do not age. Bought my pair in April 1993 and they still sound as new. In comparison, the panels of my Martin Logan Aerius electrostatic speakers need to be replaced every 5-7 years.