Brings back happy memories. I built a few of the modules of the Elektor Formant synthesizer in the early 80s. I got as far as building a VCO and VCF but ran out

Brings back happy memories. I built a few of the modules of the Elektor Formant synthesizer in the early 80s. I got as far as building a VCO and VCF but ran out of money then.