Matthias Becker recently released Cortex, a free virtual guitar amp VST effect for Windows. Unlike most other amps simulations, this one doesn't try to emulate popular guitar amps, but creates it's own unique sound. Also included in the download is Gapanessor, a free expander plug-in.

Cortex has the following controls:

• Preamp: choose between two different preamps.
• Gain: Determines the amount of gain of the preamplifier stage.
• Tube/SS: controls whether you'd like to use a tube amp or a solid state amp. You can determine the amount of tube or solid state amplification.
• Low, Mid, High, Presence: controls the EQ.
• EQ: choose between two different EQs.
• Speaker: You have four speakers and can control the volume of three of them. The result is a mix of these four speakers. Additionally you can choose between one of 17 different speaker-types per speaker. Alternatively you can use a lowpass-filter instead of a speaker.
• Volume.
• Quality.

Gapanessor has the following controls:

• Attack: Determines how fast the expander opens. It controls the compressor as well.
• Release: Determines how fast the expander reduces the volume. It controls the compressor as well.
• Compression: This controls the amount of compression. This will be removed in future versions as it's a very bad and inflexible compressor.
• Low, Medium, High: If you have a system with almost no noise, you'll only need the low control. It reduces noise with very low amplitude. Medium reduces louder noises as well, but might cut off some parts of the signal. If you have very loud noise floor, you have to use high. But then you should think about buying better equipment. But high can be used as an effect.