SoftAmp GT is a sim of “a well-known analog guitar amplifier simulator stomp-box”.
“The prototype is a solid state circuit that uses op-amps to saturate the signal and moderate filtering to shape the tone throughout the signal path. The speaker simulation is achieved by a steep low-pass filter as well as some middle-frequency manipulation to resemble different microphone positions. All controls of the original device are faithfully reproduced in this plug-in in addition to some unique ones described below.”
More great stuff from SoftAmp.