The reality is "somewhere in between". It's actually specified as a voltage source with a fixed impedance [1]. Tricks like snaking the signal in series through

The reality is "somewhere in between". It's actually specified as a voltage source with a fixed impedance [1]. Tricks like snaking the signal in series through multiple receivers don't really work; whereas tricks like sourcing +5 VDC from the connector do work. But it is correct that the current which ends up flowing through the connection is what determines the bits sent (by virtue of the receiver being an optocoupler, not an op-amps). [1] https://midi.org/specifications/midi1-specifications/midi-1-addenda/5-pin-din-electrical-specs https://midi.org/specifications/midi1-specifications/midi-1-...