OpenIEMA is an Open Source, In Ear Monitor Amplifier built as an alternative to the Behringer P2 with dual headphone outputs driven from a mono balanced XLR input, with onboard LiPo power and USB-C charging!!
| True balanced input | Neutrik XLR into an OPA1678 differential line receiver which ensures any long cable runs from the mixer stay noise free |
| Dual 3.5mm outputs | supports up to two IEM users off one beltpack, driven by a TI TPA6132A2 DirectPath amp! |
| Analog soft limiter | anti parallel LEDs act as soft limiters that clamp excess noise before you hear it! |
| Fully portable | Uses a 1S LiPo with USB C charging (MCP73831, 500 mA) and a boost converter to a clean 5 V analog rail, charges while switched off |
| Zero firmware | 100% analog signal path built for simplicity |
| 3D-printed enclosure | Includes a 3D printed enclosure with volume control all in a compact package! |
40 × 70 mm, 2-layer, designed in KiCad 10.
Schematic:
Layout:
3D View:
Designed in Fusion 360
This project uses:
- KiCad 10 for schematic capture and layout
- pcb2blender for the Blender renders
- TI TPA6132A2 + OPA1678, Microchip MCP73831, TI TPS61023
MIT
aaravj.tech · GitHub @aaravjhamb