That sine wave shaper is fascinating. Typically OpAmp-101 circuits integrate the triangle wave, but this is a poor approximation of a sine wave (since it is a q

That sine wave shaper is fascinating. Typically OpAmp-101 circuits integrate the triangle wave, but this is a poor approximation of a sine wave (since it is a quadratic), unless the output is filtered (but then the filter needs to change with the frequency, which is complex). The diode/resistor ladder is very interesting.