The Erica Synths Black 3109 VCF/VCA is a lowpass filter and voltage-controlled amplifier combo built around the AS3109 VCF integrated circuit, a contemporary version of the IR3109 chip, found on vintage Roland synths such as the Jupiter series, Juno series and the SH-101. Features 24dB/oct lowpass VCF Volume drop compensation Built-in VCA Cutofflevel attenuverter 1V/oct tracking The 3109 VCF/VCA is our attempt to recreate the iconic sound of these synths, but we also aim to improve upon it. Filters based on IR3109 had several drawbacks, including a volume drop when the resonance is increased so we added a volume drop compensation as well as a built-in VCA for more versatility in compact setups. Additionally, 1V/oct tuning is implemented so you can use this module for perfect VCF keyboard tracking and also as a VCO.
