Abstract: A speaker simulator receives a high power musical signal from a power amplifier, and a reduced power signal is extracted by a pad circuit and directed to a high-pass filter and a fan circuit which drives a cooling fan. The output of the high-pass filter is directed to a servo amplifier and a series of notch filters, prior to output from the speaker simulator. The angular momentum of the blades of the cooling fan provides an history-dependent impedance, i.e., an impedance dependent on the past values of the signal driving the fan. The history-dependent impedance produces an aesthetically pleasing distortion of the speaker simulator output.