I designed PCB based on rene's MS20. I use 13600 instead of 3080. It works well. http://www.aleph.co.jp/~takeda/radio/pdf/ms20clone.pdf http://www.aleph.co.jp/~takeda/radio/img/VCF-scheme.gif http://www.aleph.co.jp/~takeda/radio/img/g-vcf2.jpg Cheers, Motohiko Takeda Tokyo Japan