EFM ARP 4072 Filter

The Electronics For Music VCF7b is a clone of the ARP 4072 filter. Unfortunately there were a few mistakes on the PCB, which are not too hard to correct. Yves Usson's detailed instructions for making this a really nice filter can be found here. This filter sounds just like the one in my ARP Odyssey! It will self-oscillate at less than maximum resonance settings - down to very low frequencies.