I want to build this VCO circuit http://yusynth.net/archives/ElectronicDesign/H-Malvar-linVCO-1980.pdf http://yusynth.net/archives/ElectronicDesign/H-Malvar-linVCO-1980.pdf but I do not have the CD4016 CMOS switch that it says to use. Is there an alternative I could use or some other way to build a switch like that or possibly use something different that would work the same?