This small PCB lets you replace a single “block” Graetz bridge rectifier with four external Schottky diodes. The goal is a cleaner power supply with less high-frequency (HF) rectifier switching noise.

What this PCB replaces

• Original bridge in the schematic: B80C3200-2200A (D1)
• Schottky replacement on this PCB: 4× 1N5822 (D2–D5) or equivalent Schottky diodes (same footprint & suitable ratings)
• Terminals stay the same: AC~ / AC~ / + / −

Why Schottky can reduce HF noise (simple explanation)

Classic silicon rectifier diodes are PN junction devices. When they turn off, they often release stored charge (so-called reverse recovery). That creates a short, sharp current spike. In a real power supply, this spike can excite transformer leakage inductance and wiring capacitance, producing ringing and HF “hash” that can spread through the ground/rails.

Schottky diodes are majority-carrier devices and typically have negligible reverse recovery. So the turn-off transition is usually “softer” (less abrupt recovery current), which can mean:

• Less rectifier-related HF spikes on the DC rails
• Less ringing/EMI caused by transformer + wiring parasitics
• Potentially easier decoupling and a “quieter” PSU environment for sensitive audio circuits

Note: Results depend on the whole build (transformer, wiring, grounding, reservoir capacitors, snubbers). Schottky is not magic, but it can reduce one common source of HF switching artifacts.

Suggested parts (examples)

• 4× Schottky diodes shown in the schematic: 1N5822
• You may choose another Schottky diode that fits the footprint and meets your voltage/current needs

Disclaimers (read carefully)

• Mains safety: This board is intended for experienced builders. Incorrect wiring can cause electric shock, burns, fire, or equipment damage.
• Use at your own risk: You are responsible for correct assembly, insulation, fusing, enclosure safety, and compliance with local laws/standards.
• Verify polarity: Always confirm AC~ / AC~ / + / − connections and diode orientation with a multimeter before power-on.
• Component ratings: Choose diodes with sufficient reverse-voltage and current ratings for your transformer and load. Schottky diodes can have higher leakage; ensure it is acceptable in your application.
• No guaranteed sonic improvement: Any audible difference depends on the complete PSU and amplifier layout. Measurements are recommended if noise is a concern.
• No liability: The author/seller is not responsible for damage, injury, or losses resulting from use or misuse of this PCB and related modifications.