Erica Synths attempts to capture some of that classic Roland Jupiter and Juno sound with the AS3109 VCF chip in the Black 3109 VCF/VCA.
Black 3109 VCF/VCA
Looking iconically like every other deep dark Erica Synths module the Black 3109 is on a mission to capture the sound of some classic Roland gear. Vintage Roland synths such as the Jupiter-8, Juno-106 and SH-101 had filters based on the now-defunct IR3109 integrated circuit. Latvia based ALFA has produced a contemporary version called the AS3109. It contains the same high-performance voltage-controlled 4-pole filter as the original but with added stability, higher input impedance buffers and a wide transconductance range. What does that mean? I don’t know but let’s assume it’s all good.
The original filters did have a few drawbacks. The main one was the volume drop that you encountered whenever you turned up the resonance. Erica Synths has built in a spot of volume-drop compensation to keep the signals more consistent. It’s on a switch so you can choose to use it or not. The cutoff has been tuned to 1v/oct so that when it spins into self-oscillation you can repurpose it as a perfectly melodic sine wave oscillator.
The VCA section is simple but terribly useful, particularly in a compact system. You have a level knob and then a VCA CV knob to attenuate whatever envelope of other modulation sources you plug into the VCA control.
The Black 3109 is a 24dB/oct lowpass filter. Highpass and Bandpass outputs are available on the chip by Erica Synths appears to have chosen to keep it focused on the job we’d all use it for anyway.
Check out the video below, it sounds really lovely. It might give my System80 Jove filter a run for it’s Roland. Available now for €160 ex VAT.