Low Pass active Filters ,part of the measuring set ,envelope delay distorion TS2669/GCM ,the manual is on the following link : http://www.liberatedmanuals.com/TM-11-6625-922-15.pdf

КОМПРЕССОР  НА  ПОЛЕВЫХ  ТРАНЗИСТОРАХ , or fet based compressor project ,complete with pcb layout's and suitable transistor equivalents  http://www.sugardas.lt/~igoramps/article60.html

Chaos generator circuit of another strange chaotic system  http://www.researchgate.net/publication/236651194_Analysis_nonlinear_control_and_chaos_generator_circuit_of_another_strange_chaotic_system/file/e0b49518ae8bfc82da.pdf

Rikitake chaotic dynamical system , more details on this circuit : http://scialert.net/fulltext/?doi=jas.2007.232.236

 

Staircase generator using diodes ,article by H.Oscar

Philips Noise Gate .

4 Pole Moog Type VCF by EFM's mini modular synth .

Modulen Sintezator . a series of articles by Eng. Simo Lazarov featured in Bulgarian Magazine Radio Televizija Elektronika 1983 ,among the modules ..a vactrol vcf ! Component values are listed in the final article .