Thursday nights at HacDC for the next couple of weeks have been taken up with a nifty new class courtesy of Elliot - a basic electronics course in the guise of building noisemakers. From basic oscillator theory we moved on to... I couldn't make it to the second class due to a scheduling conflict, truth be told, so I don't know what was taught. Jade and I did make it to the third class which was about low-pass filters (which allow low frequencies to pass (the definition of 'low' is highly situational) but filter out high frequencies), how to vary the …