Speaker Load Emulator

HEXE Reactive Speaker Load Emulator

Reactive dummy load for a small power tube amp.

Contrary to a pure resistive dummy load (high power resistor) this one follows the non linear impedance curve of a real speaker, including the resonance peak and the slow impedance rise in the mid/high range.


  • Maximum dissipation power 5W,
  • Nominal impedance 8 Ohm,
  • 3 position Resonance switch, allows to set the resonance peak height,
  • 5 position rotary Presence switch, allows to set one of five, different impedance rise curves.


Speaker Load Emulator schematic

RLC load
RLC load

Sound samples:

Here is an interesting experiment showing what direct impact on the sound has the speaker's impedance curve (simulated by this device):