#309 Audio Connectors
Notes on miscellaneous audio connectors.
Notes
Audio signals can be carried by any kind of connection, but there are some more commonly used standard connectors for audio applications. This project is a collection of notes on some of the connectors I use/have encountered.
For more thorough coverage of the variety of audio connectors, see:
- Chapter 7 of John M. Hughes’ Practical Electronics: Components and Techniques.
- Tech Basics: Cables & Connectors - udemy course
3.5mm Connectors
Commonly used for analog audio.
3.5mm PCB-mount Stereo Socket
Example of a stereo socket with bypass. For this specific socket, pin arrangement is as below:
| Pin | Description |
|---|---|
| 1 | Left |
| 2 | Left bypass. Plug inserted: not connected; no plug: connected to LEFT(1) |
| 3 | Right bypass. Plug inserted: not connected; no plug: connected to RIGHT(4) |
| 4 | Right |
| 5 | Common/ground |
Sources:
- “10pcs DIP PCB Mount 5 Pins Female 3.5mm Stereo Audio Jack Socket Black s649_2” (aliexpress seller listing)
- Originally purchased 10pcs for US$2.99 (Apr-2015)
- Currently no longer available from this seller
- “10Pcs/lot PJ-307 3.5mm Jack Female 5 Pin Stereo Audio Headphone Connector 3.5mm TRS Audio Socket Soldering Type Connectors” (aliexpress seller listing)
- Currently offering 10pcs for SG$2.70 (Jul-2026)
6.35mm (1/4”) Connectors
Primarily used for instruments, mono and stereo.
RCA/Phono
Commonly used for analog audio and video.
XLR
- shielded audio
- professional audio
- snake - multiple XLR connectors in one bundle
Audio Adapters
e.g.
- RCA to 3.5mm plug
- XLR to RCA
- adapter packages