Electrostatic Output, Pro Bias (5-Pin)
Pro-bias electrostatic output count is the number of five-pin headphone sockets provided for the compatible 580 V Pro-bias system.
An electrostatic output carries both a high-voltage audio signal and a DC polarizing supply. It serves a different type of headphone from ordinary jack or balanced XLR headphone connections.
Electrostatic Output, Pro Bias (5-Pin) — Headphone Amp
Each Pro-bias socket counts as one output for a compatible electrostatic headphone. Two sockets therefore describe two connection points, not two channels of one stereo headphone. The five-pin connection and 580 V bias requirement must both match the headphone's intended system.
Compare output standards as well as socket counts. A six-pin Normal-bias connection belongs to a different category, and another proprietary electrostatic socket is not necessarily Pro-compatible. Multiple sockets do not guarantee independent volume controls or unrestricted simultaneous use. Check those operating conditions separately; the count alone does not describe audio voltage swing, distortion or sound quality.