Power Supply Unit "Energy Ultra-Quad"
- Board size - 100×100 mm
- AC outputs - Up to 4 AC outputs
- DC outputs - Up to 4 DC outputs, rectified, regulated
- Compatibility - DAC Rev 1.x and Rev 2.x
- Features - "Virtual Capacitor" noise rejection technology
⚠️ Warning! This PSU operates with high voltage (220–240 VAC). Working with high voltage can be dangerous and may result in serious injury or damage if handled improperly. This design is intended for users who are familiar with electrical safety and DIY electronics. Always ensure proper insulation, grounding, and safe assembly practices.
Linear Regulated Power Supply "Energy Ultra-Quad" for DAC Projects - Overview
The "Energy Ultra-Quad" is a transformer-based linear regulated power supply unit with dimensions of 100 × 100 mm, designed specifically for DAC revision 2.x projects presented on this website.
The design uses two independent PCB-mounted analog transformers to provide dedicated isolated supply rails for the DAC sections. It provides up to 4 AC outputs and up to 4 regulated, rectified DC outputs. To form a center-tapped dual-polar voltage rail, use the J1 PCB solder jumper to combine two of the outputs.
Additionally, it offers the option to implement a "Virtual Capacitor" (Nazar's electronic capacitor) circuit for enhanced noise rejection. Four LM317 linear regulators are required to provide the regulated outputs. The PCB supports both DPAK (TO-252) and SOT-223 package footprints.
Usage Notes
- This PSU provides both AC and regulated DC outputs; ensure correct connections depending on the target DAC board requirements.
- While the standard linear outputs (LM317) are fully sufficient for DAC Rev 2.x, you can optionally populate the "Virtual Capacitor" scheme. Make sure you are familiar with the pros and cons of this approach in audio circuits.
- Verify transformer wiring, pinouts, and output voltages before powering the system for the first time.
- Ensure proper insulation and safe handling of mains voltage at all times.
Design & Safety Compliance
To ensure a high level of electrical safety and prevent any potential tracking or arcing issues, the high-voltage section of the PCB has been designed in strict accordance with the IPC-2221A standard and IEC 62368-1 insulation requirements:
- Creepage and Clearance: Creepage distances between the live AC lines (Phase/Neutral) and the low-voltage DC planes are kept at a safe margin (over 6.0 mm) to deliver reinforced isolation. The high-voltage section utilizes 1mm milled isolation slots (air gaps) around the transformer mountings and phase lines to guarantee maximum dielectric strength and eliminate surface creepage currents.
- No AC Copper Pours: High-voltage AC tracks do not use copper pours, keeping capacitance coupling and noise leakage to a minimum.
- Safety Components: The input filtering stage is strictly designed for safety-rated X2/Y1 components.