David12 & Folkfreak are correct that the McIntosh MHA100, as well as pretty much any other general purpose headphone amplifier, would be unsuitable for use with Stax electrostatic headphones. For several reasons: All Stax electrostatics produced in recent decades require a 580 volt bias voltage. They also require a balanced signal pair for each channel, to support push-pull action on the diaphragm. Each of those signals must be at much higher voltages than the signals supplied to dynamic headphones, and work into much higher impedances (145,000 ohms in the case of David’s phones, resulting in lower currents than in the case of dynamic headphones). Finally, the connector is completely different, requiring 5 pins to supply the two balanced signal pairs + the bias voltage, rather than the two signal pins (one for each channel) + ground of a standard 1/4 inch headphone connector.
Regards,
-- Al
Regards,
-- Al