how to get a asymmetrical LFO?

[walters]

1.) HOw do i get a Asymmetrical LFO waveform?



2.) On most pedals i have are all Symmetrical LFO's
    i would like to make is Asymmetrical

[toneman]

clip it at the top.
clip it at the bottom.
but, not so much off the top, please.
T

[Eb7+9]

... check out the MS-20 circuit (... & socket the FETs) ...

[Paul Perry (Frostwave)]

The magic phrase is "steering diodes". Most LFO oscillators work by charging & discharging a capacitor via a resistor. If the charge/discharge resistor is replaced by two resistors, each with a diode in series, then you can make it so you use one resistor to charge & the other to discharge.. now imagine that the two resistors are joined at the cap.. and now imagine that they are actually the two sides of a pot, with the wiper point being where the cap is.. :idea:

and this is often seen with 555 timer circuits.
What is trickier is to get a variable assymetry LFO wher ethe symmetry control doesn't interfere wiht the frequency. Anyone got a good example?

[walters]

Very good Perry