Analog Multiplexers

Different multiplexing setups can be used for monophonic CV outputs depending on whether polyphonic outputs are also desired. If you only want to play a monophonic analog synth from the GR-300 and don't feel like building six log converters (which is understandable because it's a HUGE pain), then you can build only one log converter, and use the analog multiplexers to control its inputs. One analog mux can be used to select which of the GR-300's six period control voltages goes to the log converter's CV input. A second analog mux can be used to determine which transpose voltage gets sent to the log converter's output mixer to shift its output to the right pitch value for that string.

If you are really insane and want a polyphonic system (like me), then you need six long converters anyway. Adding a monophonic output to that type of system requires only one analog mux to select which log converter's output goes out.

In both cases, you will need additional analog muxes for envelope follower output, etc. These multiplexers select which string's control voltages are going to the monophonic outputs for pitch CV, envelope, etc. The muxes switch in response to the three-bit binary number from the loudest-string-priority circuit.