4 layers72.4 × 69.8 mm
4 layers27.1 × 55.9 mm
OpenIEMA
aaravjhamb/openIEMA7A high quality open source In Ear Monitor Amplifier!! (IEMA for short)
- Size
- 27.1 × 55.9 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 56
- Nets
- 35
- Pads
- 180
- Tracks, vias
- 271, 26
- Pours
- 2
- Routed
- Yes
- KiCad
- KiCad 9.0 (file 20241229)
- Created
- 1 Oct 2026
- Updated
- 2 Nov 2026
Overview
OpenIEMA is an open-source printed circuit board by aaravjhamb, from the aaravjhamb/openIEMA repository on GitHub. It is a 4-layer board of 27.1 × 55.9 mm with 56 parts on 35 nets, routed with 271 tracks and 26 vias.
It is built around the OPA1678ID, TPA6132A2RTE and BAV99. Its parts include 18 capacitors, 16 resistors, 6 diodes, 5 connectors and 4 ICs.
Main components
3
OPA1678ID
SOIC-8-150mil-18V~-2.25V、2.25V~18V -40℃~+85℃ 10pA 10pA 110dB 16MHz 2 2mA 2uV/℃ 4.5V~36V 4.5nV/√Hz@1kHz 500uV 50mA 9V/us Built-in compensation、ESD protection Rail-to-rail output SOIC-8-150mil Operational Amplifier ROHSTexas InstrumentsAudio Amplifiers
TPA6132A2RTE
WQFN-16-EP(3x3)-40℃~+85℃ 0.02% 100dB 100dB 2-Channel 2.1mA 2.3V~5.5V 25mWx2@16Ω Automatic mute/no-noise switch、Enable/shutdown function、Digitally programmable gain WQFN-16-EP(3x3) Audio Amplifiers ROHSTexas InstrumentsAudio Amplifiers
BAV99
SOT-231 Pair Series Connection 1.25V@150mA 100V 215mA 250mW 4A 4ns 500nA@80V SOT-23 Switching Diodes ROHSNexperiaSwitching Diodes
README
README.mdOpenIEMA
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!!
Key Features
| 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! |
PCB
40 × 70 mm, 2-layer, designed in KiCad 10.
Schematic:
Layout:
3D View:
Case
Designed in Fusion 360
Credits
This project uses:
- KiCad 10 for schematic capture and layout
- pcb2blender for the Blender renders
- TI TPA6132A2 + OPA1678, Microchip MCP73831, TI TPS61023
License
MIT
aaravj.tech [blocked] · GitHub @aaravjhamb
Parts
56| Qty | Value | Footprint | References |
|---|---|---|---|
| 6 | 10k | Resistor_SMD:R_0402_1005Metric | R7, R8, R9, R10, R12, R13 |
| 4 | 100n | Capacitor_SMD:C_0402_1005Metric | C9, C10, C15, C16 |
| 4 | 10u | Capacitor_SMD:C_0402_1005Metric | C6, C7, C8, C14 |
| 4 | LED | LED_SMD:LED_0402_1005Metric | D1, D4, D5, D6 |
| 3 | 100k | Resistor_SMD:R_0402_1005Metric | R6, R11, R14 |
| 3 | LOGO | LOGO | G***, G***, G*** |
| 2 | 1k | Resistor_SMD:R_0402_1005Metric | R4, R15 |
| 2 | 1u | Capacitor_SMD:C_0402_1005Metric | C17, C18 |
| 2 | 22u | Capacitor_SMD:C_0402_1005Metric | C4, C5 |
| 2 | 4.7u | Capacitor_SMD:C_0402_1005Metric | C1, C2 |
| 2 | 47u - polarized | Capacitor_SMD:CP_Elec_6.3x7.7 | C11, C12 |
| 2 | 5.1k | Resistor_SMD:R_0402_1005Metric | R1, R2 |
| 2 | AudioJack3 | PJ320A:Jack_3.5mm_PJ320A_Horizontal | J4, J5 |
| 2 | BAV99 | Package_TO_SOT_SMD:SOT-23 | D2, D3 |
| 1 | 100nf | Capacitor_SMD:C_0402_1005Metric | C13 |
| 1 | 10k pot | Potentiometer_THT:Potentiometer_Piher_PT-6-V_Vertical | RV1 |
| 1 | 10u, ceramic | Capacitor_SMD:C_0402_1005Metric | C3 |
| 1 | 1uH | Fixed_3D:L_Taiyo-Yuden_NR-40xx | L1 |
| 1 | 2k | Resistor_SMD:R_0402_1005Metric | R3 |
| 1 | 4.7k | Resistor_SMD:R_0402_1005Metric | R16 |
| 1 | 732k | Resistor_SMD:R_0402_1005Metric | R5 |
| 1 | Battery | Connector_JST:JST_PH_B2B-PH-K_1x02_P2.00mm_Vertical | J1 |
| 1 | FerriteBead | Resistor_SMD:R_0805_2012Metric | FB1 |
| 1 | MCP73831-2-MC | Fixed_3D:DFN-8-1EP_3x2mm_P0.5mm_EP1.7x1.4mm | U1 |
| 1 | OPA1678 | Package_SO:SOIC-8_3.9x4.9mm_P1.27mm | U3 |
| 1 | SW_SPDT | Button_Switch_SMD:SW_SPDT_PCM12 | SW2 |
| 1 | TPA6132A2RTE | Package_DFN_QFN:WQFN-16-1EP_3x3mm_P0.5mm_EP1.6x1.6mm_ThermalVias | U4 |
| 1 | TPS61023DRLR | TPS61023:SOT-563_L1.6-W1.2-P0.50-LS1.6-BR | U2 |
| 1 | USB_C_Receptacle_PowerOnly_6P | USB_C_HRO:USB_C_Receptacle_HRO_TYPE-C-31-M-17 | J3 |
| 1 | XLR3 | NC3FD-H:Jack_XLR_Neutrik_NC3FD-H_Horizontal | J2 |
Questions
How big is the OpenIEMA PCB?
It measures 27.1 × 55.9 mm and has 4 copper layers, 1.6 mm thick.
What parts does the OpenIEMA use?
56 parts, built around the OPA1678ID, TPA6132A2RTE and BAV99. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the OpenIEMA KiCad files?
From the aaravjhamb/openIEMA repository on GitHub, at the commit this page was made from: the board is PCB/OpenIEMA.kicad_pcb and its schematic PCB/OpenIEMA.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the OpenIEMA design in my own project?
Its repository states no licence, so its author keeps all rights: ask aaravjhamb before reusing the design.
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