Quick Q about circuit splitting

[Andyhannaman]

In part of a pedal design, I am using an SPDT toggle after FX1 to either use FX2 or FX3. After these two circuits (essentially layed out in parallel, but one one used at a time), do problems arise when recombining? Even though the FX not activated is out of the circuit, does the signal seeing the back end of this "off" circuit pose issues?  I imagine one way to solve this if so is to just use a DPDT and route the input and output of each circuit through it to fully isolate, but if this isn't necessary that would be good to know.  Bad hand drawings included.

[idy]

You would hear any noise from the unused circuit. *Maybe* if you grounded the unused input that would be *maybe* better, but that requires another switch pole anyway, so second sketch is a good deal safer.

This leaves aside the literal reading of your question, whether the unused circuit would load the output of the one being used. It might, depends on the circuits being proposed. Volume control that isn't buffered would be an obvious culprit. Either way it's not something worth taking a chance on.

[Andyhannaman]

That's what I figured, and now thinking of it there is an unbuffered volume right at the output of one of the circuits (one knob fuzz). Will definitely do the second the be safe. Thanks for the input!

[FiveseveN]

The simplest way would be to switch the output instead of the input.

[antonis]

The simplest way would be to switch the output instead of the input.

Not so simple 'cause a splitter right after FX1 should be needed..

[FiveseveN]

As I understood it, the one with the "unbuffered volume" is either FX2 or FX3, so I assumed FX1 could drive both of them.