Attached is an image of the invention of antiparallel diodes to lower the voltage. It would be 15v to 11.5v
In the Scale Z forum in Spain it indicates that this is a good voltage for digital.
Each pair of diodes in antiparallel lowers the voltage by 0.7v
[url=https://ibb.co/k6SWSSG][img]https://i.ibb.co/0VGdGGn/diodos-antiparalelo.jpg[/img][/url]
