CV and gate are the two voltage signals analog synths use to talk to each other. CV (control voltage) tells the synth what to do — usually which pitch to play — while the gate signal tells it when to play and for how long. Together they let one device trigger and control another using electricity instead of digital messages like MIDI.
If you’re moving from a DAW into hardware, Eurorack or semi-modular synths, understanding CV and gate is the key that unlocks patching. Here’s how it works in plain English.
What control voltage (CV) does
A control voltage is exactly what it sounds like: a voltage used to control a parameter. The most common job is pitch. On most Eurorack and many vintage-style synths, pitch follows a 1 volt per octave standard — raise the CV by one volt and the oscillator jumps up an octave. Roland’s older systems used a different Hz/V scheme, which is why not all vintage gear plays nicely together without conversion.
But CV isn’t limited to pitch. You can patch a control voltage into almost anything:
- Filter cutoff (so an envelope or LFO sweeps the filter)
- Amplitude via a VCA
- LFO rate, oscillator modulation, effect parameters and more
To understand where CV gets routed, it helps to know the core building blocks — see what VCO, VCF and VCA are.
It’s worth remembering that a control voltage is just a number expressed as a voltage. Whether that voltage ends up moving a pitch, opening a filter or speeding up an LFO depends entirely on where you patch it. The same envelope can drive a filter on one cable and a VCA on another at the same time. This is the heart of modular thinking: voltages are generic, and the destination decides what they mean.
Two kinds of CV come up constantly. Pitch CV is meant to be precise and stable, because small errors translate into out-of-tune notes. Modulation CV — from an LFO, envelope or random source — is meant to wobble and move, so accuracy matters far less. Knowing which kind you’re dealing with tells you how fussy to be about levels and tuning.
What the gate signal does
The gate is a simple on/off voltage. When a key is held or a step is active, the gate goes high; when you release, it drops to zero. The synth’s envelope generator reads that gate to know when to start its attack and when to begin its release. In short:
- CV = which note (the pitch)
- Gate = note on/off and duration (the timing)
A closely related signal is a trigger, which is just a very short pulse used to fire a one-shot event like a drum hit, rather than holding a note open.
The distinction between gates and triggers matters in practice. A gate stays high for as long as the note is held, so it can sustain an envelope — useful for pads and held notes. A trigger is a momentary blip that simply says “go now” and then disappears, which is perfect for percussion or for re-firing an envelope on every step. If a sound cuts off too early or refuses to sustain, the length of your gate is often the first thing to check.
CV and gate vs MIDI
MIDI and CV/gate solve the same problem in different ways. MIDI is a digital protocol that sends note numbers and data over a single cable; CV and gate are analog voltages, usually carried on separate patch cables — one for pitch, one for the gate.
| CV and Gate | MIDI | |
|---|---|---|
| Type | Analog voltage | Digital data |
| Pitch | One CV cable (e.g. 1V/oct) | Note numbers |
| Timing | Separate gate cable | Note on/off messages |
| Polyphony | One voice per CV/gate pair | Many notes per cable |
Because each CV/gate pair handles one voice, classic analog setups are often monophonic by nature — which is exactly why so many of the best monophonic synths rely on CV and gate. To drive analog gear from a DAW, you use a MIDI-to-CV converter that turns MIDI notes into pitch CV and gate. For the wider picture of integrating both worlds, see our guide on connecting a hardware synth to your DAW.
Neither approach is “better” — they suit different jobs. MIDI is tidy, repeatable and great for polyphony, automation and recall, which is why it dominates studio work. CV and gate are immediate and tactile: there is no menu, no channel to set, just a voltage doing one thing. Many modern rigs use both at once, letting MIDI handle the sequencing while CV handles the hands-on modulation that gives hardware its character.
Where you’ll meet CV and gate
- Semi-modular synths like the Moog Mother-32 and Matriarch, or the Behringer Neutron, expose CV/gate jacks so you can patch beyond the default routing — see the best semi-modular synths for hands-on examples.
- Eurorack systems live and breathe CV — sequencers send pitch CV and gates, while modulation sources like Mutable Instruments Marbles generate voltages to animate everything. If you’re curious where to begin, our Eurorack for beginners guide is a good next step.
- Drum machines and sequencers often output triggers to fire analog drum modules.
If this is your entry point into modular, our beginner overviews on what a modular synth is and how to patch a modular synth show CV and gate in action.
How to start patching CV and gate
The simplest useful patch is a sequencer or keyboard driving a single voice. Take the pitch CV output and patch it to the oscillator’s 1V/oct input, then take the gate output and patch it to the envelope generator’s gate or trigger input. Route that envelope to a VCA so the note actually opens and closes. With those three connections you have a complete monophonic voice: the right pitch, played at the right time, with shape.
From there you build outward one cable at a time. Patch a second envelope or an LFO into the filter cutoff for movement. Send the gate to two envelopes so amplitude and filter open together. Because every connection is visible on the front panel, the fastest way to learn is to make one change, listen, and only then add the next.
Common mistakes to avoid
- Swapping pitch and gate cables. If a note sounds but is stuck on one pitch, or plays the right pitch but never stops, you have probably crossed the two cables.
- Mixing pitch standards. Patching a 1V/oct source into Hz/V Roland gear (or the reverse) will track wildly out of tune. Convert between the two rather than patching directly.
- Forgetting the VCA. A correct pitch and gate still need an envelope and VCA to be heard; without them a voice can drone or stay silent.
- Gate too short to sustain. If held notes clip off early, your gate length or sequencer step length is the usual culprit.
Practical tips for using CV and gate
- Match the standards. Most Eurorack is 1V/oct; check before mixing in vintage Roland gear that uses Hz/V.
- Watch voltage levels. Gate signals come in different heights (commonly around 5V to 10V); a module usually triggers fine as long as the gate is tall enough.
- Keep pitch and gate together. If a note plays the wrong pitch or never sounds, you’ve likely swapped or forgotten one of the two cables.
Frequently asked questions
Is CV and gate the same as MIDI?
No. MIDI is digital data sent over one cable, while CV and gate are analog voltages, normally on two separate cables — one carrying pitch, the other the note-on signal. A MIDI-to-CV converter bridges the two so a DAW can drive analog gear.
What is 1V per octave?
It’s the most common pitch standard for control voltage: every extra volt raises the oscillator by one octave. Most Eurorack and modern analog synths follow it, which lets gear from different makers track pitch together.
Do I need CV and gate if I use MIDI?
Not necessarily. If your synth speaks MIDI and you sequence from a DAW, MIDI alone is enough. CV and gate matter most with semi-modular and Eurorack systems, where patching voltages gives you deeper, hands-on control.
What is the difference between a gate and a trigger?
A gate stays high for the whole length of a note, so it can sustain an envelope through its hold stage. A trigger is a brief pulse that simply fires an event and then disappears, which suits drum hits or re-starting an envelope on each step.
