[sdiy] (OT) Doepfer MIDI-CV oddity

[Steve Ridley]

I've seen a similar problem which I solved with a pull-up in the midi out circuit.

The output device was just open collector TTL gate with an output resistor, and I don't think it was shutting off efficiently, any leakage current etc being pulled through the opto at the Midi In end. I added an extra pull-up resistor - a few K, can't remember exact value - between the open collector output pin and +5v - and it cleaned the signal up nicely.


Steve