[sdiy] Tri to Sine Shaping - Another Way

[Grant Richter]

For a stupidly simple one, you can use a 10K over a 3.3 volt MOV.

http://www.musicsynthesizer.com/Waveshapers/movs.html

I prototyped it and got 0.5% THD, works better than a FET (2-3% THD)  
non-linear resistor.