Key points
- Audio signals are heard after they reach an output or monitoring path.
- Control voltage changes a parameter, but it is not automatically part of the audible signal path.
- Module labels and voltage ranges vary by manufacturer, so check the manual before patching.
The simplified audio path
sound source
tone shaping
level control
monitoring
This diagram is intentionally simplified. Oscillators produce periodic signals. A filter changes the balance of frequencies. A VCA controls signal level in response to a control input. The final output stage should be appropriate for the equipment that follows.
The control path
A gate can trigger an envelope. The envelope then changes over time and can control the VCA, allowing a note to start and stop with a defined shape. An LFO provides repeating modulation and can be routed to pitch, filter cutoff, amplitude, or another destination.
| Module | Typical role | Important caveat |
|---|---|---|
| VCO | Oscillator or sound source | Pitch tracking standards and ranges can vary |
| VCF | Frequency shaping | Filter type and slope affect the result |
| VCA | Voltage-controlled level | Can process audio or control signals in many systems |
| Envelope | Time-varying control signal | Needs a trigger or gate source |
| LFO | Repeating modulation | Some oscillators span LFO and audio rates |
Patch deliberately
Read the module manual and confirm input and output roles. Avoid connecting outputs directly to other outputs. Start monitoring at a low level. A wall diagram can explain roles and flow, but it cannot replace manufacturer-specific voltage and safety guidance.
Frequently asked questions
What is the difference between audio and CV?
Audio is a signal intended to be heard after monitoring. Control voltage changes a parameter. The electrical distinction can overlap in modular systems, so the patch context matters.
Does every patch need a filter?
No. The oscillator, filter, VCA chain is a useful subtractive-synthesis example, not a requirement for every patch.
What does a VCA do?
A VCA changes the level of a signal according to a control input. In a basic note patch, an envelope often controls the VCA.
Sources and further reading
Turn reference into wall art
Explore TrebleMaker Studio formats on Etsy. Product artwork is a visual reference and decorative object, not formal course material.