Vibrato vs tremolo

The short answer

Vibrato and tremolo both take a steady sound and make it pulse in time, and both are driven by the same kind of slow control wave. The one thing that separates them is what that wave moves. Vibrato is a periodic variation of pitch: the note bends slightly up and slightly down, over and over, the way a singer or a violinist makes a held note shimmer. Tremolo is a periodic variation of volume: the pitch holds dead steady while the loudness swells and dips, the throb you hear from a vintage amplifier or a helicopter passing overhead.

Both effects lean on an LFO, a low frequency oscillator, which is just a slow control wave that sweeps a setting up and down a few times a second. Point that wobble at pitch and you get vibrato. Point the very same wobble at volume and you get tremolo. Same engine, different target. If you remember nothing else from this page, remember that one line.

Vibrato: a wobble in pitch

When a singer holds a long note and lets it warble, that warble is vibrato. The pitch rises a little above the target note and falls a little below it, cycling a few times a second. A natural, musical vibrato sits around five to seven cycles per second, with a swing small enough that your ear still hears one steady note rather than two separate ones. Speed the wobble up or widen the swing and it stops sounding like a singer: it turns nervous, seasick, or comic.

Because vibrato moves pitch, it is a close relative of the effects that thicken a voice. A chorus is essentially a stack of tiny, gentle vibratos mixed underneath the dry sound, which is why a deep vibrato blended only part of the way in starts to sound less like one wobbling voice and more like doubling. Vibrato and chorus are the same idea at different doses.

Tremolo: a wobble in volume

Tremolo leaves the pitch alone and moves the volume instead. Picture a hand riding a volume knob up and down in a steady rhythm: loud, soft, loud, soft. That is tremolo. Engineers call it amplitude modulation, because the amplitude, the height of the wave that your ear reads as loudness, is what the LFO is modulating. The pitch never changes; only the level does.

You have heard it on old electric-piano and guitar recordings, where the sound seems to pulse or shimmer in place, and in the choppy, stuttering texture of a sound being switched rapidly on and off. A slow tremolo is a gentle sway; a fast one turns into a buzzy, broken flutter. It never makes the note higher or lower, though, which is the whole point of the contrast.

Seeing the difference

The cleanest way to keep them straight is to look at one tone under each effect, side by side. The wave carries both facts at once: how far apart its cycles sit tells you the pitch, and how tall it stands tells you the volume.

One effect slides the wave sideways in time; the other pushes it up and down in level. Written as math, the split is just as clean: vibrato puts the slow wobble inside the pitch, while tremolo lays it on top of the volume.

Why they get confused

Given how different they look on paper, why does almost everyone mix them up? Part of it is that both are simply described as a slow wobble, and the ear does not always cleanly separate a small pitch change from a small volume change, especially once the wobble speeds up. And part of it is history: some classic guitar amplifiers shipped with a circuit labeled vibrato that actually modulated volume, which is true tremolo, and at least one famous unit labeled its pitch effect tremolo. The mislabeling stuck, and generations of players learned the two words backward.

To tell them apart by ear, listen for whether the note itself bends. If the pitch seems to waver, like a voice on the edge of tears, it is vibrato. If the pitch stays rock steady and only the loudness pulses, like something throbbing in and out, it is tremolo. When in doubt, hum along: you can hold a steady pitch straight through a tremolo, but a vibrato will keep sliding out from under you.

Vibrato and tremolo in patchd

patchd ships a real Vibrato node in its Studio voice-fx rack, the same rack that holds chorus, reverb, and the rest. It does exactly what this page describes: a slow LFO bends the pitch up and down. Its Rate sets how fast the wobble runs, and around five to seven cycles a second lands on a natural singer's vibrato. Its Depth sets how far the pitch swings, and its Mix blends the wobble against the dry voice, so pulling it back from full turns a pure vibrato into a chorus-like doubling.

The control that gives the node its character is Shape: at zero it is a smooth, even sine, and at full it becomes a random, unsteady warble. That drunk wobble is the tremor behind patchd's aged, drunk, and ghost character voices. The Vibrato node is documented at zero latency, so it never adds any delay to what you are monitoring while you talk or sing.

There is one honest gap to name. patchd does not ship a dedicated tremolo, or volume-wobble, node. The closest thing is the Ring Modulator: as you drop its Frequency toward the very bottom of its range, under roughly thirty cycles a second, its effect drifts out of clangorous robot territory and toward a choppy, on-off feel that borders on amplitude modulation, and raising its Carrier Bleed lets the original tone back through, morphing the metallic effect toward the volume wobble that tremolo is. That is a family resemblance, not a true tremolo node, and we would rather say so than pretend otherwise.

One last honest point: the wobble in every one of these nodes comes from an LFO that lives inside the node. patchd has no separate, routable LFO you can wire to any control you like. Instead each modulation node carries its own, and you meet it through that node's Rate, which is its speed, and Depth, which is its amount. For the underlying idea, see what is an LFO.

The takeaway

Vibrato wobbles pitch; tremolo wobbles volume. Both are the same slow LFO pointed at different targets, which is exactly why they are so easy to confuse and why some vintage gear even printed the labels backward. Watch the wave and you can always settle it: cycles bunching and spreading is vibrato, a height that swells and dips is tremolo. In patchd you get a real, zero-latency Vibrato node with a Shape control that runs from a smooth sine to a drunk warble; there is no dedicated tremolo node, though the Ring Modulator at a very low setting leans that way.

patchd is a pre-launch Windows audio mixer with a Studio voice-fx rack whose modulation nodes include Vibrato, chorus, flanger, phaser, and ring modulator. If you want a mixer that can add a real singer's warble, or a ghostly one, to your voice in real time, join the waitlist and get notified when it ships. The Studio tier is $39.99 per year, and the real-time engine is identical on the Free and Studio tiers.