Although my schematic is not standard
I'm trying to build a proper PSU for my Alactron 500 series rack since PSU's for this model are no longer being produced. I need help determining if my design is correct, especially regarding grounding and connections for AC/DC, bridge rectifiers, and DC-.

Color Codes:

Purple: AC Red: DC+ Black: DC- Green: Ground I'm unsure if the grounding is connected properly, and I'm also concerned about preventing ground loops. Additionally, I believe a capacitor might be needed at the DC- line, along with fuses and components to smooth out the currents, as this PSU will be used with audio equipment.

Although my schematic is not standard, it should be clear enough to understand. I'm seeking practical advice from anyone experienced in electronics. Thank you

 

Can you use two bridge rectifiers with a center tapped transformer to create a plus and minus voltage?
I think you should look into that. A better way is to use two isolated windings not a center tapped winding.

With some transformers you can see where the center tap output is and how it is made from two separate windings. They twist and solder those two wires together to form the center tap. If you can get to that (perhaps under some tape) you can separate the two windings and make two isolated windings. Simply unsolder the two leads and gently untwist them.

 

Before going much farther you need to know the current requirements at each voltage. That matters a whole lot. Aside from that, while the connections on the drawing call pin #5 "ground", it is actually the power supply common return, which may not be at all related to the typical (green wire) electrical safety ground connection.
I am not at all familiar with the " Alactron 500 series rack ", but I am guessing that it is a sound system of some kind. That means that noise on the DC power sources will also matter quite a bit..