Midi thru trouble

[Derop]

Hello community. I am struggling with this project a lot and it seems nothing is working. Basically i used this schematics, followed it 100%, i also contacted the creator who told me it would work fine. But it doesn't want to

To test it i use esx1 as master and pass the signal to minilogue xd via this midi thru.

I ve done ton of research, i used different schematics, different opto but still nothing.

I power it using 5v cellphone charger. I even tried 9v battery brought down to 5v with 7805, but nothing.

Any ideas?

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[ixtern]

For me the hardest thing was to find pins 4 and 5 on MIDI socket - pinout is from the front or from behind? So attaching properly labelled pinout.

I had used some different values for 6N138 but as it not worked reliable for me (maybe because I'd not used Schmitt triggers), I had switched to 6N137.

Here is my schematic with 6N137 which I've used in two synthesizers so far.

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[Derop]

Thank you so much for your reply! In fact... from what you are saying.. i must had soldered the 4 and 5 pins incorrectly. I will try changing them and update the topic

[Derop]

[Grumble]

I have lowered the resistor designated as R101 in your schematic to 68 ohm and put an LED in series with that resistor so I have an indicator if the midi is coming in.

[ixtern]