A member of the MIDI Controllers FB group asked the following question and I thought the resolution would be good info to have going forward:
[Does anyone know] how to convert the new midi 3,3volt (midi out) signal so it can be read by a Tyros 4 that only reads the ‘old’ type 5volt signal?
The Tyros 4 has a very standard MIDI implementation:
The 6N137's output side uses a 5 V supply, but its input works with any 5 mA current at a forward voltage of about 1.5 V. Any standard-compliant MIDI output is able to drive that, even when using 3.3 V.
Why are you asking this question? Is there an actual problem?
I was asking for a fellow member of the MIDI Controllers Facebook group. He has since returned the unit to the seller. I just now asked if there was a problem with the unit. Awaiting response.