Low-Noise 24 V Audio PSU Design

I’m putting together a single-rail power supply for sensitive audio gear and need a clean, hum-free output. The brief is straightforward: • Topology: prefer an LDO-based regulator front-ended by a capacitance-multiplier stage (or an equally quiet alternative you can justify)... (Budget: $30 - $250 USD, Jobs: Analog Electronics, Audio Engineering, Circuit Design, Electrical Engineering, Electronics, Embedded Systems, Manufacturing Engineering, PCB Layout, Prototyping, Signal Processing)