melodic sawtooth

Even in this era of programmable, polyphonic synthesizers, interest in simple, monophonic keyboard instruments remains. Many FORM- ANT owners are still proud of their, probably first, home-built synthesizer and are still on the look-out for new circuits for the generation of exotic sounds. For all those, here is an easy- to-build circuit that can convert a sawtooth signal at its input into an output of double the frequency and half the peak value of the input signal (figure 11. Comparator IC1transform s the sawtooth signal into a rectangular 2 15V 1 melodic sawtooth H Millian P2=0 P2.,max. 85407-1 signal (see figure 2). Adder IC2com- bines the original input signal and the rectangular signal. An additional LFO (low frequency oscillator) connected as shown pro- vides pulse-width modulation of the rectangular signal, which has a greatly beneficial effect on the output signal. When switch S1is set to position b, it is possible to inject a rectangular signal whose frequency is indepen...