Well, actually … while cogitating about this circuit, I made the unfortunate mistake of consulting the data sheet for the LM7812 which is commonly used in Kosmo and Eurorack power supplies, including in the Frequency Central power supply, and I found out that the minimum voltage that it might put out is 11.5V so in theory we would have to design to that constraint.
you guys together seem to be tearing apart the fabric of the eurorack community at the same time as solving this voltage reference issue!
First of all thanks to you two, ive been catching up on some well needed, “fill in the blanks on rather patchy know how”, searching various aspects of the chat and getting to the bottom of this.
The current draw from the Vdd reference pins of the ms14504’s, I just went to test this, needless to say the only midimuso I have sitting here has been pilfered for parts much to my dismay. in the words of terminator (who most definitely had headroom for his voltage reference) i’ll be back.
But with a small enough series resistor I believe the TL431 based circuit can handle a dropout of less than a volt.
Antoine this is indeed what I have been working to this whole time. To be honest I assumed because such a large bulk of modular supplies have 7812’s I thought everyone was working towards 11.5 anyway it was just a round up. Even the deeper supplies are around that amount.