BLM Acid N Sons 3109 VCF

3109-Based Filter

BLM ACID n SONS FILTER
WIDTH: 6HP
CURRENT: +64mA -64mA

24DB VCF + VCA

This module has the modern 3109 filter chip. The older 3109 chip is found in the vintage Roland keyboards like SH-101. What I did is add resonance audio drop out compensation and precision resistors for the exponential converter. The module will easily track 5+ octaves when in full self oscillation. Band pass was also added as a bonus. The band pass steals the show, as many have not heard an SH-101 with band pass.

-24db low pass
-18db band pass

-Internal VCA for easy voice building
-FM Bi Polar CV input for the Filter
-Envelope Input for the VCA
-Dual Audio Inputs, one direct, and the other with over drive.

https://www.etsy.com/listing/1345409503/blm-acid-n-sons-3109-vcf?click_key=2cc89bf4619a42ff86162f03c5e28561b3ab69e5%3A1345409503&click_sum=741794ce&ref=shop_home_active_1

https://reverb.com/item/63142874-blue-lantern-blm-acid-n-sons-3109-filter-vcf-2022-black