MPOA

Give your audio project a considered mains input

Bring three useful mains-conditioning functions together in one assembled module. The MPOA from Audio products combines DC blocking, EMI suppression and an over-voltage protection circuit for integration into audio equipment powered from a 230 V AC supply.

It is a practical option when you are building an amplifier or planning a mains-conditioning project and want these functions in one board, supplied with a wired terminal plate, terminals and a fused mains switch.

Three functions for your audio setup

• DC blocking: designed to reduce the DC component on the AC mains supply. This can help with mechanical transformer hum caused by DC offset, particularly in equipment using large toroidal transformers.
• EMI filtering: a mains-filter circuit suppresses conducted electromagnetic interference entering through the supply.
• Over-voltage protection: an integrated protection circuit with a stated threshold of 270 V AC.

Address the source of transformer hum

Some household loads draw current unevenly across the mains waveform, creating a DC offset that can contribute to mechanical hum in a transformer. The MPOA targets this specific cause. Results depend on the mains conditions and the connected equipment; hum from grounding, vibration or other faults needs a different solution.

Assembled for integration into your build

The package includes the fully assembled board and a wired terminal plate with terminals and a mains switch with fuse. Faston connectors provide wiring connections, while the diode arrangement uses individual heat sinks. The board measures 150 × 135 × 45 mm (L × W × H), helping you plan the space required inside a suitable enclosure.

Technical specifications

• Manufacturer: Audio products.
• Mains supply: 230 V AC.
• Published load ratings: 2500 W or 14 A continuous; 3500 W repetitive peak. Confirm the appropriate load, fuse and wiring requirements for your installation.
• EMI-filter choke: 4 mH, Cu 1.8, 14 A.
• Over-voltage protection threshold: 270 V AC.
• Capacitor bank: 65,400 µF.
• Diodes: ultra-fast types with individual heat sinks.
• Connections: Faston terminals.
• Dimensions: 150 × 135 × 45 mm (L × W × H).

Plan a proper mains installation

All parts of this circuit are directly connected to mains voltage. This is an integration module requiring a suitable protective enclosure and correctly designed mains wiring. Installation must be carried out by a suitably qualified person; disconnect the mains supply before handling or servicing.

Ready to add mains conditioning to your project? Select the MPOA above, or contact Audio products to discuss compatibility, load requirements and the right configuration for your equipment.