Connections & Patching¶
Patching is where the magic happens. MICRORACK uses a simple, color-coded system to make signal routing intuitive.
The Pin Header Standard¶
Instead of bulky patch cables, MICRORACK uses standard 2.54mm male pin headers for all inputs and outputs. This allows you to use:
| Cable Type | Description |
|---|---|
| Standard Jumper Wires | Cheap and widely available from electronics suppliers |
| MICRORACK Patch Cables | High-quality, flexible cables designed for the system |
| Breadboard Wire Kits | Pre-cut lengths in various colors |
Tip: For firmer connections (especially for frequently-used interfaces), double-row male pin headers can be used per the mechanical specification.
Color Coding¶
MICRORACK follows a strict color-coding standard for pin headers:
| Color | Function | Description |
|---|---|---|
| Blue | Input | Audio or CV signals entering a module |
| Red | Output | Audio or CV signals leaving a module |
| Black | Utility / GND | Ground, clock sync, power extension, stylus voltage |
I/O Placement Convention¶
Per the MICRORACK specification, inputs are typically placed on the left side and outputs on the right side of modules, at the top edge of the board.
Patching Best Practices¶
Basic Rules¶
- Outputs to Inputs: Always connect a Red pin (Output) to a Blue pin (Input)
- Never connect two Outputs: Connecting two Red pins together can cause electrical contention
Splitting Signals (Mults)¶
To send one output to multiple inputs:
- Use "stackable" jumper wires that allow multiple connections
- Use a small breadboard area to create a passive mult
- Connect multiple wires to the same output pin (up to 2-3 destinations)
Note: Per the electrical specification, each signal should have at least two output pins that duplicate the signal. This makes it easier to patch one signal to multiple destinations.
Input Summing¶
Many MICRORACK modules sum multiple inputs together:
- Each input typically has 2+ pins that are summed internally
- You can connect multiple sources to create complex modulation
- This is useful for mixing CV signals (e.g., LFO + envelope → filter cutoff)
Improve Cable Management¶
- Keep cables tidy to avoid accidentally pulling modules out
- Use consistent color coding for different signal types (audio vs CV vs gate)
- Write complex patches down to recall them later
The color coding makes it easy to trace signals: follow Red to Blue connections through your patch.
Module Chaining¶
MICRORACK modules can be chained together in various ways to create complex signal paths.
Signal Patching Across Breadboards¶
Signals can be patched between breadboards just as easily as within a single board. For long runs, we recommend:
- Keeping the boards physically close together
- Using shielded cables for sensitive audio signals
- Maintaining the color-coding convention (Red output → Blue input)
Chaining Techniques¶
| Technique | Description | Use Case |
|---|---|---|
| Serial | Output → Input → Output → Input | Effects chains, filters in series |
| Parallel | One output to multiple inputs | Modulation distribution, audio splitting |
| Feedback | Output looped back to earlier input | Self-oscillation, complex timbres |
Clock & Gate Chaining¶
For sequenced and rhythmic patches:
- Use Black (Utility) pins for clock signals
- Chain clock from master sequencer/clock module to all slaves
- Gate signals follow the same Red → Blue convention as audio
Tip: When building large patches across multiple breadboards, sketch your signal flow on paper first. This helps plan module placement and minimize cable lengths.