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The essential connector for modern headset and video projects. PJ-392A features a 4-Pin (TRRS) configuration, allowing support for Stereo Audio plus Microphone or Composite Video. Panel mount design with included nut.
Stereo? Check. Microphone? Check. Standard headphone jacks only have 3 pins (Left, Right, Ground). The PJ-392A 3.5mm Socket upgrades your project with a 4-Pin TRRS configuration. This extra "pole" allows you to connect headsets with built-in microphones, or even transmit analogue video signals (like on Raspberry Pi or older camcorders).
Secure Panel Mounting Designed for professional enclosures, the PJ-392A features a threaded cylindrical body that fits into a standard 6mm hole. Secure it tight with the included knurled nut for a flush, wiggle-free installation. The gold-plated internal contacts ensure a crackle-free connection that lasts.
Specifications
Model: PJ-392A.
Connector Size: 3.5mm (1/8 inch).
Configuration: 4-Pin / 4-Pole (TRRS).
Mount Type: Panel Mount (Chassis).
Panel Cutout: ~6mm.
Contact Plating: Gold Flash / Nickel.
Rating: 30V DC / 0.5A.
Insertion Force: 3-20N.
Lifespan: >5000 Cycles.
Compatibility & Platform Support
Headsets: Compatible with standard mobile headsets (CTIA/OMTP wiring dependent on your soldering).
Microcontrollers: Great for adding audio I/O to ESP32 or Raspberry Pi audio hats.
Video: Can carry Composite Video + Stereo Audio for retro gaming projects.
Key Applications & Projects
Headphone Repair: Replace broken jacks on laptops or amps that need Mic support.
Custom Aux Inputs: Add an Aux-In port to your car stereo or Bluetooth speaker.
Raspberry Pi: Break out the A/V jack to a custom case.
Virtual Technician: Wiring & Safety ⚠️
Pinout Identification: The pins are usually not labelled. You must use a multimeter in "Continuity Mode" to map the physical pins to the plug segments (Tip, Ring 1, Ring 2, Sleeve).
CTIA vs OMTP:
CTIA (Standard Android/Apple): Tip=L, R1=R, R2=GND, Sleeve=Mic.
OMTP (Old Nokia/Sony): Tip=L, R1=R, R2=Mic, Sleeve=GND.
Wire the socket according to the standard you need!
Soldering: The lugs are small. Use a fine-tip soldering iron and pre-tin the wires. Do not hold the iron on the pin for too long (>3s) or you risk melting the internal plastic insulation.
Accessories
Included in the Package:
1 x PJ-392A 4-Pin 3.5mm Socket
1 x Mounting Nut
Frequently Asked Questions (FAQ)
What is the difference between PJ-392 and PJ-392A? The standard PJ-392 is typically a 3-Pin (Stereo) socket. The PJ-392A is the 4-Pin (TRRS) version, supporting Mic or Video.
Will this work with regular headphones (without mic)? Yes! A standard 3-pin headphone plug will physically fit. The "Mic" contact inside the socket will simply connect to the plug's Ground sleeve (shorting Mic to Ground), which is standard behavior and works fine for audio playback.
What size hole do I need to drill? You need a 6mm diameter hole for the threaded neck to pass through.
Can I use this for video? Yes, if your source device uses a 3.5mm AV cable (like Raspberry Pi or TV boxes), the 4th pin can carry the Composite Video signal.
Does it come with the nut? Yes, a matching metal mounting nut is included.
Are the pins labeled? No, these industrial components rarely have labels. Use a multimeter to verify which pin connects to the Tip, Rings, and Sleeve.
Is it waterproof? No, it is an open frame connector.
Can I use it on a PCB? It has solder lugs designed for flying wires, not PCB through-holes. For PCB mount, look for "PJ-320" or similar square models.
What is the contact material? Usually Gold-plated or Silver-plated brass for good conductivity.
Does it support balanced audio? Technically, yes, if you wire it for Hot, Cold, and Ground, but it is primarily designed for unbalanced Stereo + Mic.
Why is my audio mono? Check your soldering. You might have bridged the Left and Right pins, or you are using a TS (Mono) plug.
Can I use this to fix my laptop jack? If your laptop uses a panel-mount jack (rare), yes. Most laptops use PCB-mount jacks, so this physically wouldn't fit inside.
Is the body plastic or metal? The main cylindrical body is usually Plastic, with a metal threaded bushing at the front.
How do I wire it for an iPhone headset? Wire it to the CTIA standard: Tip=Left, Ring1=Right, Ring2=Ground, Sleeve=Mic.
Does it switch speakers off when plugged in? No. The PJ-392A is a simple socket. It does not usually have "Normally Closed" switch pins to auto-mute speakers.
What is the max panel thickness? The threaded neck is short, typically suitable for panels up to 3mm thick.
Can I use thick wire? The solder lugs are small. We recommend 26AWG to 30AWG wire.
Is the ground isolated from the panel? Since the body is plastic, the electrical ground is isolated from the metal panel (unless the bushing itself is tied to Sleeve, which varies by batch—check with a meter).
Will it fit a 2.5mm plug? No, this is strictly for 3.5mm plugs.
Why is the insertion so tight? New jacks can be stiff. It will loosen slightly after 10-20 insertion cycles.


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