Casio HT3000 with hardware filter ADSR, VCF LFO, Resonance LFO, data entry LFO & Midi clock sync for all LFOs :)
(https://kg.kg/wp-content/uploads/2021/01/ht3000-mods.jpg)
Video: https://youtu.be/VkVMXOtuoQE (https://youtu.be/VkVMXOtuoQE)
Schematics : https://kg.kg/casio-ht3000-njm-2090-vcf-modifications/ (https://kg.kg/casio-ht3000-njm-2090-vcf-modifications/)