SoftAmp GT is a free VST virtual emulation 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.
AMP – general amplifier family :
- Tweed – classic American clean-sound amps.
- British – crunch and moderate gain.
- California – modern hi-gain amp with a deep low-end.
MOD – gain structure of the amplifier :
- Hot wired (same as hi-gain but with a high-freq boost).
MIC – virtual microphone position :
- Classic – far from the speaker.
- Center – the most bright setting.
- Off-axis – slightly offset microphone that provides smoothed high-freq response.
The original stomp-box was somewhat criticized for having a symmetrical hard-clipping saturation and there were a lot of attempts to modify the circuit to provide smoother tube-like sound by the community. Variations included using different op-amps and using a bipolar transistor to introduce the asymmetrical clipping. This plug-in takes this concept further by introducing a special control :
CLIP – clipping mode :
- Normal – standard hard-clipping modeled after the TLC2262 op-amp.
- Soft – abstract symmetric soft-clipping stage.
- Triode – virtual 12AU7 triode stage.
The most interesting is the Triode setting. It effectively replaces every op-amp in the circuit with a triode stage accurately modeled using the same engine used in the SoftAmp 3OD plug-in. It will perform asymmetric soft-cliping with dynamic behaviour that depends on the tube overdrive level that will produce a moderate amount of even harmonics. The overall difference is subtle, but it’s there. A good test would be listening to the effect applied to the sinusoidal input.