What is the best way to wire an onboard preamp with a 3pdt toggle switch for active/passive modes?
Is it ok to use the Madbean standard wiring method?
From my understanding "active" and "passive" refers to whether a circuit uses power or not to function.
so I don't understand your question.
If you're asking if you can use the standard wiring to bypass the preamp and go straight to whatever its it's connected to then yes.
But a preamplifier is an active circuit by definition because you cannot amplify a signal without a power source.
hope this helps
Daniel