Specs for the standard Alge Headsets are
Microphone:
Polar pattern hypercardioid
Type dynamic
Frequency range 100 to 8,000 Hz
Sensitivity 0,72 mV/Pa (- 63 dBV)
Max. SPL 130 dB (for 1% THD)
Impedance 230 ohms
Recommended load impedance >500 ohms
Headphones:
Type closed-back, circumaural dynamic headphones
Frequency range 150 to 5,000 Hz
Sensitivity 90 dB SPL/mW
Rated impedance 200 ohms/channel
Lightweight ASL headset have a 200ohm mic and 400ohm headphone.
Not sure which is optimal but both setups work with Alge amps.