The thought process that went into building a compact yet comprehensive starting modular synth system for my Learn Modular Synthesis course that covered a wide range of both East and West Coast techniques.
Different oscillators and MIDI to CV converters may have varying ideas of what voltage a given note produces, and what pitch should you hear as a result. If there is a difference, in most cases it can be dialed out with a pitch knob or transpose switch. However, there are occasions when you need the assistance of an additional module to settle these disagreements.