Just wondering what the unwritten rules are about pcb design layout when setting out a circuit with a lfo??
power supply,
audio signal
lfo?
keep x away from z?
etc etc?
I use a two sided board. The bottom of the board includes a ground plane (and other traces... unless the board is extremely simple).
The LFO circuitry is kept away from the audio stuff as much as possible (but we're talking about a 55mm X 55mm pcb here... how far away could it be?), usually closer to the power supply jack.
The biggest thing that makes a difference for me is that the ground to the LFO circuitry is isolated and just goes to a pad. That pad is connected directly to the power jack ground or some other ground point (kind of like star grounding). The audio stuff ground is just connected directly to the ground plane on the board by vias or directly, etc.
Traces for LFO out and audio are kept away from each other if possible.
All this usually works for me.