From Hackaday article
" A simple transistor current source linearizes the waveform in no time. Raw sawtooth waves are “rich in harmonics” which is synth-geek code for “a bit grating”, but it will surely do well with a little filtering. "
Source :
https://tristandabbles.wordpress.com/2011/12/13/555-lco-javascript-get-freaky-now/
http://hackaday.com/2016/06/18/very-clever-555-bassline-synthsequencer/
