The Cast Iron from After Later Audio is a 4HP wide Stereo VCA. The volume and panorama can be controlled on the module, and there is a separate control voltage input for both parameters. As the audio input is normalized from L/mono to R, mono signals can also be used. A stereo signal is always present at the audio output. Modulating the volume with a fast LFO in the audio section or an oscillator creates interesting sideband effects. Cast Iron can be connected to the Bartender and USB-2CH modules via a rear connector. This enables the extension of Bartender and a reduced stereo input (compared to Bartender) and, in combination with USB-2CH, the level processing of the signal from the audio interface.