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Hey all, I know we're all familiar with this mainstay of effects, but how exactly does the LFO work? What's causing the switching?
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Q3 is the LFO. The signal at its collector is fed back to its base through the three 1uf caps. Those caps and their resistors to ground form a simple phase shift or delay if you will, so when the collector voltage rises, that rise takes a brief interval to rise at the base. And a rising base signal will bring the collector down, which will an interval later bring the base down, and so on as oscillation.
Changing the resistances changes the RC time factor, and so the frequency or speed. Changing the capacitances would do it too, but that is impractical here.Education is what you're left with after you have forgotten what you have learned. -
pretty clever, thanks!Comment
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They do the samething in tube amps, but with a triode instead of a transistor. Principles are the same.Education is what you're left with after you have forgotten what you have learned.Comment
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