Please ignore the statement I made about the output not being symmetrical I had a diode turned the wrong way. Now it puts out a beautiful sine and sounds even better. Tom > Someone asked how to use the hybrid-OTA to build a MS20 > filter...... > > http://www.xavax.com/efm/pdf/vcf8h.pdf > > It might be hard to believe but this sounds very good. > > Tom > >