Changing Dirtbag LFO

[sodapep]

Hello all

Just bought some Dirtbag PCB's to mess around with. I was wondering if it was possible to swap out LFO's in the circuit. My thought was to replace the modulation pot with an LDR and wire up a different LFO circuit with various wave forms and other controls like speed and depth, rather than just mix.

Any thoughts? Thank you!

[LaceSensor]

The Chorus / Vibe switch changes caps, maybe you can add a rotary for more caps / different ranges of modualtions as a quick change?

[madbean]

The easiest thing you could do is replace R53 with a pot for a speed control. Use a 1MC. Wire lug3 to one pad of R53. Solder a resistor between lugs 2 and 1 (4k7 should do it) then wire lug1 to the other pad of R53. The resistor sets the maximum speed of the LFO.

[sodapep]

The Chorus / Vibe switch changes caps, maybe you can add a rotary for more caps / different ranges of modualtions as a quick change?

Good call. I was thinking about using a blend pot to blend the two caps together and possibly using more extreme cap values to get further mod reaches on either end of the pot.

[sodapep]

The easiest thing you could do is replace R53 with a pot for a speed control. Use a 1MC. Wire lug3 to one pad of R53. Solder a resistor between lugs 2 and 1 (4k7 should do it) then wire lug1 to the other pad of R53. The resistor sets the maximum speed of the LFO.

That's kind of what I figured, it seemed similar to some other LFO's that are around. Thanks!

A thought - since the modulation control isn't just a variable resistance to ground, perhaps two LDR's could be used in place of the pot in series with their junction being the output (pin2) of the 'pot'. Then have two LED's set for alternating brightness flash on one of the  LDRs each.