by JimN » 27 Dec 2020, 16:05
Richard, the circuit for a Marvin (the original 1960s model) is the same as that for a Stratocaster of the day.
For example:
<https://www.google.com/url?sa=i&url=http%3A%2F%2Fddwiring18.lasagradellacastagna.it%2Fdiagram%2Ffender-stratocaster-noiseless-wiring-diagram&psig=AOvVaw0wsWZ9HQjv6VuG3hnsRiWN&ust=1609167710034000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCPjH1sq37u0CFQAAAAAdAAAAABA8>
There are loads more available on the internet.
More recent models of the Marvin (the Anniversary onward) have an extra facility for switching in the neck pickup to any pickup selection. That too is available online if that's what you want.