LFO circuit for Tremolo Help with bias setting!

Started by SismoJFV, September 10, 2020, 01:35:19 PM

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SismoJFV

Hey I am trying to build a LFO for a Tremolo, however most of the designs that I am interested in (they have shape selection available :icon_lol:) are circuits that use polarized power supplies with common ground (+/ -9v and ground) . I don't know how can I adapt those circuits for a guitar pedal with a common battery supply or 9V non polarized DC supplies.



Here is an example of a circuit (only the LFO section) that I already built successfully, but with the +/- 9v.

https://harrisonshimazublog.wordpress.com/2015/05/08/vca-tremolo/

Is there a way to turn that circuit to work with a virtual ground approach :icon_question:?

ElectricDruid

I don't see any reason why that couldn't be done the usual way: Turn "-9" into ground, turn "+9" into "+V" and turn "ground" into your virtual ground / midpoint bias voltage.

The 2164 VCA is a bit borderline for running at 9V. Its minimum supply is +/-4V, so 9V is only just enough - but still within spec, so "legal" from that point of view.

Do a search for "converting bipolar supply circuits to single supply" or similar. There must be a ton of stuff out there, and on here too.


SismoJFV

Quote from: ElectricDruid on September 10, 2020, 02:43:05 PM
I don't see any reason why that couldn't be done the usual way: Turn "-9" into ground, turn "+9" into "+V" and turn "ground" into your virtual ground / midpoint bias voltage.

The 2164 VCA is a bit borderline for running at 9V. Its minimum supply is +/-4V, so 9V is only just enough - but still within spec, so "legal" from that point of view.

Do a search for "converting bipolar supply circuits to single supply" or similar. There must be a ton of stuff out there, and on here too.


Thank you for your help! I will try that today!