Haven’t done a tremolo in a while, so let’s remedy that with the original 4-transistor Colorsound Tremolo (the re-issue is the 3-transistor version). Originals used 2SC945 transistors (BCE pinout), but I’ve laid this out for more common NPN transistors with CBE pinout. You might want to use a C100k pot for the Speed control. Here’s the schematic for reference.
