CMOS Synthesizers - Beavis Audio Research
Chip Basics For our experiments, we'll use a couple basic chips: 40106 Hex Inverting Schmitt Trigger: This chip contains 6 individual Schmitt triggers. A Schmitt trigger is a comparator circuit that incorporates positive feedback. What this means is that when a high signal (positive voltage defined as '1') is applied to the input pin, the output pin generates a low signal (ground voltage defined as '0). This simple circuit can be connected to a resistor/capacitor pair to rapidly turn on an off. 4040 Binary Counter/Divider: This simple logic chip takes an input square wave and generates oscillations at 8 outputs with a frequency related to the input frequency. 4051 Eight Channel Analog Multiplexor/Demultiplexor: The voltage status of the three address pins A, B and C determines which of the eight channels presents its voltage to the common connection pin. Note: All schematics on this site use the following notation for potentiometer tapers: A = Logarithmic, B = Linear Using Your Effects!
Related: Synth Hacking
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