====== How to "safely" extend MIDI interface ====== According to the standard, MIDI cables should not exceed 15 meters. What if I have to go far beyond the 15 meters ?? There are some expensive extenders out there but I have successfully used this simple and affordable extension over common XLR cables, using RS485 line. {{:notes:midiextension.png|}} In few words, midi output is taken on pin 5 of din, it is negative logic and could be open collector. Thus the 10k pull-up resistor before feeding the signal to the RS485 driver. At the receiver, only a couple of resistors to limit current on the midi input optocoupler. An external power supply is needed because - according to the standard - pin 4 of midi out connector is linked to a resistor then to Vcc so it could not be enough to supply the external driver.