Leaderboard

It's about 6N137 optocoupler as replacemant for 6N138 on MIDI8 and MIDI-IO Boards. Differences is that the 6N137 is a CMOS level output. More than that the 6N137 will allow you to significantly increase the speed between two MIDIbox. From datasheet maximum speed is 10 MBaud/s instead of 100KBaud/s for the 138. On the MIDI board you just have to remove the 4K7 resistor and replace 1K pull-up for a 10K. Done! Best regards Bruno