BinKey

pj-3001f-thonkiconn-35mm-mono-jack

6 min read

Important Note

This entire repo was AI created - including all of the data within. The intent was to A) help me with my personal electronics inventory; and B) see how I could use AI to make that process a bit easier. DO NOT TRUST!

PJ-3001F 3.5mm Mono Phone Jack (Thonkiconn)

Overview

Standard 3.5mm mono phone jack connector, widely known in the Eurorack modular synthesizer community as “Thonkiconn” jacks. These PCB-mount jacks feature switching contacts and are the de facto standard for CV/Gate connections in modular synthesizers, as well as general audio applications requiring compact mono connections.

Location

Cabinet-7, Bin 9 - Thonkiconn Jacks

Images

PJ-3001F Thonkiconn 3.5mm Mono Jack

Specifications

Physical Specifications

  • Connector Type: 3.5mm (1/8”) mono phone jack
  • Mounting: PCB mount, through-hole
  • Body Material: Black plastic housing
  • Contact Material: Nickel-plated brass
  • Switching: Normally closed switching contact
  • Panel Thickness: Suitable for standard PCB and panel mounting
  • Thread: M7 x 0.75 threading

Electrical Specifications

  • Voltage Rating: 30V DC (typical)
  • Current Rating: 1A (typical)
  • Power Rating: 30W maximum
  • Contact Resistance: <30mΩ
  • Insulation Resistance: >1000MΩ
  • Operating Temperature: -25°C to +85°C
  • Insertion Force: 10-40N

Mechanical Specifications

  • Mating Cycles: 5,000+ insertions
  • Retention Force: 10N minimum
  • Panel Cutout: 6mm diameter
  • PCB Hole: 1.0mm diameter for pins
  • Overall Length: ~13mm from panel surface

Pin Configuration

Contact Layout

The jack has multiple contacts for different functions:

Tip (T) ---- Signal/Hot
Sleeve (S) -- Ground/Return
Switch (SW) - Normalling/Switching contact

Pin Functions

  • Tip (T): Main signal contact (hot/positive)
  • Sleeve (S): Ground/return contact (shield/negative)
  • Switch (SW): Normally closed switching contact for normalling
  • Additional Pins: Some variants have multiple switch contacts

Normalling Operation

  • No Plug Inserted: Switch contact closed to normalling point
  • Plug Inserted: Switch contact opens, breaking normalling connection
  • Signal Path: Tip and sleeve carry the audio/CV signal

Applications

Eurorack Modular Synthesizers

  • CV Inputs/Outputs: Control voltage connections between modules
  • Gate Inputs/Outputs: Trigger and gate signal routing
  • Audio Inputs/Outputs: Audio signal patching between modules
  • Normalling: Internal signal routing when no patch cable connected

Audio Equipment

  • Headphone Outputs: Mono headphone connections
  • Line Inputs/Outputs: Unbalanced audio connections
  • Instrument Inputs: Guitar, bass, and other instrument connections
  • Effects Loops: Send/return connections in audio processors

DIY Electronics

  • Arduino Audio Projects: Simple audio input/output connections
  • Breadboard Prototyping: Temporary audio connections
  • Test Equipment: Signal injection and monitoring points
  • Educational Projects: Audio circuit demonstrations

Professional Audio

  • Patch Bays: Signal routing and normalling applications
  • Mixing Consoles: Auxiliary sends and returns
  • Recording Equipment: Direct input connections
  • Live Sound: Monitor and effects connections

Circuit Examples

Basic Audio Input (Arduino)

const int audioPin = A0;
const int outputPin = 9;
 
void setup() {
  pinMode(audioPin, INPUT);
  pinMode(outputPin, OUTPUT);
  Serial.begin(9600);
}
 
void loop() {
  int audioValue = analogRead(audioPin);
  int outputValue = map(audioValue, 0, 1023, 0, 255);
  
  analogWrite(outputPin, outputValue);
  
  Serial.print("Audio Level: ");
  Serial.println(audioValue);
  
  delay(10);
}

CV Input with Normalling

const int cvPin = A1;
const int normalPin = A2;
const int outputPin = 10;
 
void setup() {
  pinMode(cvPin, INPUT);
  pinMode(normalPin, INPUT);
  pinMode(outputPin, OUTPUT);
}
 
void loop() {
  int cvValue = analogRead(cvPin);
  int normalValue = analogRead(normalPin);
  
  // Use CV input if present, otherwise use normal value
  int controlValue = (cvValue > 10) ? cvValue : normalValue;
  
  int pwmValue = map(controlValue, 0, 1023, 0, 255);
  analogWrite(outputPin, pwmValue);
  
  delay(1);
}

Simple Audio Mixer

const int input1Pin = A0;
const int input2Pin = A1;
const int outputPin = 9;
 
void setup() {
  pinMode(input1Pin, INPUT);
  pinMode(input2Pin, INPUT);
  pinMode(outputPin, OUTPUT);
}
 
void loop() {
  int input1 = analogRead(input1Pin);
  int input2 = analogRead(input2Pin);
  
  // Simple mixing (average)
  int mixed = (input1 + input2) / 2;
  int output = map(mixed, 0, 1023, 0, 255);
  
  analogWrite(outputPin, output);
  
  delay(1);
}

PCB Design Considerations

Footprint

  • Panel Hole: 6mm diameter for jack body
  • PCB Holes: 1.0mm diameter for pins
  • Pin Spacing: Standard spacing for PJ-3001F footprint
  • Keep-out Area: Allow clearance around jack body

Layout Guidelines

  • Ground Plane: Connect sleeve to ground plane
  • Signal Routing: Keep tip connections short and direct
  • Decoupling: Add capacitors for AC coupling if needed
  • ESD Protection: Consider TVS diodes for exposed inputs

Mechanical Design

  • Panel Thickness: Ensure proper threading engagement
  • Nut Torque: Don’t over-tighten mounting nut
  • Strain Relief: Consider cable management for permanent installations
  • Accessibility: Allow easy access for plugging/unplugging

Installation

PCB Mounting

  1. Drill Holes: Create appropriate holes for pins and body
  2. Insert Jack: Place jack from component side
  3. Solder Pins: Solder all connections from solder side
  4. Mount to Panel: Secure with mounting nut from front
  5. Test Connections: Verify continuity and switching operation

Panel Preparation

  1. Mark Location: Mark center point for jack placement
  2. Drill Hole: 6mm diameter hole for jack body
  3. Deburr: Remove sharp edges from hole
  4. Test Fit: Ensure jack fits properly before final assembly

Wiring

  1. Identify Pins: Use multimeter to identify tip, sleeve, and switch
  2. Solder Connections: Use appropriate gauge wire for application
  3. Strain Relief: Secure wires to prevent stress on solder joints
  4. Test Operation: Verify proper switching and signal continuity

Troubleshooting

Common Issues

  • No Signal: Check solder joints and pin identification
  • Intermittent Connection: Clean contacts or replace jack
  • Mechanical Failure: Check mounting nut tightness
  • Switching Problems: Verify switch contact wiring

Testing Procedures

  • Continuity Test: Check tip-to-tip and sleeve-to-sleeve continuity
  • Switch Test: Verify switching operation with plug insertion
  • Insulation Test: Check isolation between contacts
  • Mechanical Test: Verify smooth plug insertion/removal

Sourcing Information

Supplier

Alternative Sources

  • Thonk: Original “Thonkiconn” branding supplier
  • Mouser: Various manufacturers available
  • DigiKey: Professional-grade alternatives
  • Modular Addict: Eurorack-specific suppliers
  • Love My Switches: Specialized connector suppliers

Specifications to Match

  • 3.5mm mono configuration
  • PCB mount with switching contacts
  • M7 x 0.75 threading
  • Standard pin spacing
  • Normalling capability

Eurorack Context

Why “Thonkiconn”?

  • Thonk: UK-based supplier popular in DIY Eurorack community
  • Standard: These jacks became the de facto standard for Eurorack
  • Compatibility: Ensures compatibility across different module manufacturers
  • Cost-Effective: Good balance of quality and price for DIY builders

Eurorack Applications

  • CV Connections: ±5V or ±10V control voltage signals
  • Gate Signals: 0V/+5V or 0V/+10V trigger signals
  • Audio Signals: ±5V or ±10V audio range
  • Clock Signals: Timing and synchronization between modules

Normalling in Eurorack

  • Internal Routing: Connect internal signals when no patch cable present
  • Mult Functionality: Create multiple outputs from single source
  • Default Connections: Provide sensible defaults for module operation
  • Flexible Patching: Override defaults with external connections

Storage and Handling

Storage Recommendations

  • Dry Environment: Prevent corrosion of contacts
  • Anti-Static: Use anti-static packaging if needed
  • Organization: Keep with other audio connectors
  • Temperature: Room temperature storage

Handling Tips

  • Gentle Installation: Don’t force into PCB holes
  • Proper Tools: Use appropriate soldering iron temperature
  • Clean Contacts: Keep contacts clean for reliable operation
  • Avoid Over-Tightening: Don’t over-torque mounting nuts

Tags

connectors, jacks, audio, 3.5mm, mono, thonkiconn, eurorack, cv-gate, pcb-mount, switching, normalling cabinet-7 status-available

Notes

These PJ-3001F jacks are essential components for Eurorack modular synthesizer builds and general audio applications. The “Thonkiconn” designation comes from their popularity in the DIY Eurorack community, where they became the standard choice for CV/Gate connections. The switching contacts enable normalling functionality, allowing modules to have internal signal routing that can be overridden by external patch cables. Store in Cabinet-7, Bin 9 for easy access during modular synth builds and audio projects. The low cost and reliable operation make them ideal for both prototyping and production use in electronic music equipment.

Graph View

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