Amazon.com: LM YN High-Voltage Power Supply Module DC-DC ±45-390V Adjustable Step-Up ZVS Capacitor Charge Ultra High Voltage Adjustable Output : Electronics
How to add power supply filter capacitor to amplifier board.
Transformer less Capacitor DC power supply circuit and design
High Precision Low Ripple Variable High Voltage DC Power Supply 4u Bench Rack Mount Chassis for Capacitor Charging - China High Voltage Power Supply and DC Power Supply