Little Plate

About Little Plate

We had two objectives when designing Little Plate: to create a lifelike reproduction of the classic EMT 140 plate reverb sound, and to extend its features in ways not possible in an analog effect. We hope you’ll love using Little Plate as much as we loved making it. It wasn’t enough for us to just go to someone’s studio and study an EMT 140 for a day or two. We went out and collected five of them so that we could live with them, tune them up, detune them, modify them, and study them extensively. Then we distilled what we learned into a plug-in that we think exemplifies classic plate reverb sound–dense, smooth, and a little bit dark. Then we went farther by extending the maximum reverberation time to infinity. We also included modulation that creates subtle, lush movement within the reverb tail. Whether you’re looking for an authentic recreation of classic plate reverb, or looking to go farther, we think you’ll find that Little Plate is more than up to the task.

What is a Plate Reverb?

The plate reverb is one of the most unlikely heroes in recording history, but it changed the sound of records forever. Simultaneously enormous and understated, the original wood-clad EMT 140 weighs in at about 600 pounds. It’s not pretty. It’s a piece of equipment that’s essentially made to be hidden away in a utility closet far from the studio’s loud live room. But despite it’s humble, boxy exterior, the EMT 140 is undoubtedly the most iconic example of plate reverb, and remains a truly ingenious invention. Before the plate, when engineers wanted to add realistic reverberation to a recording they had to pipe sound into physical rooms or echo chambers. The EMT 140 instead uses a magnetic transducer to vibrate a massive sheet of metal, sending the result back to the engineer via a pickup that captures the resulting reverberation. While other early reverberation devices use springs, this tends to create a metallic and fluttery sound. The plate, however, is capable of dense and smooth reverberation unlike anything the world had heard. While it doesn’t exactly sound like a real room, it has a beauty of its own, which is why plate reverb is still such a sought-after sound even many decades later. EMT 140s are getting hard to find though, and replacement parts even harder. Not to mention their sheer size and weight keep them out of reach of the average studio. But don’t worry, we’ve done the heavy lifting for you. Little Plate faithfully recreates the 140 vibe right inside of your favorite DAW.

Decay

The Decay control determines how long reverberation continues after an audio signal enters Little Plate. It is the primary control for shaping the overall size and character of the reverb. Shorter decay settings produce a tighter, more controlled ambience resembling a small room, while longer decay settings produce larger, more spacious and cavernous reverberation.

Relationship to the EMT 140

On the original EMT 140, decay time was regulated by a mechanical damper positioned near the vibrating metal plate.

• Moving the damper closer to the plate reduced the duration of the vibrations and shortened reverberation.
• Moving the damper farther from the plate allowed the vibrations to continue for longer. Even with the damper positioned as far away as possible, the original EMT 140 could produce only about five seconds of reverberation at 500 Hz. Little Plate extends this range considerably. Moving the Decay control into its red region provides reverberation times beyond the capabilities of the original hardware. The maximum decay time before entering infinite mode is approximately 60 seconds.

Understanding Decay Measurements

The decay times displayed on the control are based on RT60 measurements at 500 Hz. RT60 represents the time required for the reverberation level to decrease by 60 decibels. The 500 Hz reference corresponds to the measurement convention used on the original EMT 140 control panel. In plate reverberation, decay time depends on frequency. Different frequency ranges do not necessarily fade at the same rate. Consequently, changing the Decay setting affects not only the duration of reverberation but also its tonal characteristics. High frequencies decay more quickly than other frequency ranges at every Decay setting. Low-frequency behavior changes substantially as decay time increases:

Decay Setting	Sonic Character
Short	Tight, controlled reverberation
Long (approximately 4–5 seconds)	Warmer sound with more pronounced low-frequency buildup
Extended (up to approximately 60 seconds)	Exceptionally long reverberation tails exceeding the original hardware
Infinite	Continuously sustained, evolving reverberation

[!TIP] Longer decay settings can produce increased low-frequency buildup. Use the Low Cut control to reduce excessive bass and maintain clarity.

Infinite Decay Time

Turning the Decay control fully clockwise activates Infinite Decay. In this mode, reverberating audio does not naturally fade away. Instead, sounds can remain within the simulated plate indefinitely. The reverberation is not completely static. As it continues, the sound evolves and gradually becomes darker. Additional audio entering the effect interacts with the existing reverberation, continually changing the resulting texture. This capability makes infinite decay useful for ambient sound design, evolving musical textures, and sustained atmospheric effects.

[!WARNING] Monitor output levels carefully when using Infinite Decay. Sending sustained or loud audio into the effect can cause energy to accumulate within the simulated plate. Because the reverberation does not naturally fade, this buildup can produce unexpectedly high output levels. [!TIP] Automate the Decay parameter in your DAW to transition smoothly into and out of Infinite Decay. This allows you to capture and sustain specific musical phrases or individual passages within the reverberation. [!TIP] Experiment with performing instruments live through Little Plate while Infinite Decay is active. This technique can transform the effect into a compositional tool rather than simply a conventional reverberation processor.

Low Cut

The Low Cut control removes low-frequency content from the incoming audio before that signal enters the reverb. It affects only the signal being processed by the reverberation engine. The dry, unprocessed audio remains unaffected by Low Cut. This distinction allows excessive bass to be removed from the reverb without changing the low-frequency content of the original signal.

Why Low Cut Matters

In a plate reverb, low frequencies can decay more slowly than higher frequencies. This behavior can produce a buildup of bass energy within the reverberation tail, particularly at longer Decay settings. Excessive low-frequency content may make the resulting reverberation sound muddy, boomy, or poorly defined. Increasing the Low Cut setting reduces the amount of bass entering the plate simulation.

[!TIP] If the reverb sounds muddy or boomy, increase Low Cut. This can improve clarity while preserving the low frequencies of the original dry signal. Low Cut is especially useful with longer decay times.

Mod

The Mod switch introduces subtle modulation into the reverberation. This creates small variations within the reverb tail that can produce a thicker, smoother, and more animated sound. The effect becomes particularly noticeable at longer decay settings. Modulation introduces gentle pitch variations that are not possible with a traditional mechanical plate reverb.

Audible Characteristics

The modulation effect is generally easier to hear on instruments containing sustained or clearly defined pitches. Examples include:

• Keyboards: Subtle movement within sustained notes and chords.
• Guitar: Added thickness and motion in the reverb tail.
• Vocals: Increased richness and gentle pitch movement. The modulation is typically less obvious on highly percussive material, such as drums. When enabled, Mod can add subtle movement and richness to reverberation without fundamentally changing the character of the original signal.

[!TIP] Experiment with Mod when using very long decay settings. Combining modulation with Infinite Decay can produce particularly rich, lush, and continuously evolving reverberation textures.

Mix

The Mix control determines the balance between the processed reverberation signal and the original unprocessed audio.

Mix Position	Result
0% — Dry	Only the original unprocessed signal is audible
Intermediate	A combination of dry signal and reverberation
100% — Wet	Only the processed reverberation signal is audible

Traditional Plate Reverb Mixing

The original physical plate reverbs did not include a built-in wet/dry Mix control. Instead, engineers typically routed audio to the plate using an auxiliary send on a mixing console. The resulting reverberation was returned to the console through a separate return channel or fader. This arrangement allowed several instruments to feed the same plate at different levels. The engineer could then control the overall reverberation level using a single return fader. Sharing one reverberation processor across multiple instruments can create the impression that those sources occupy a common acoustic space.

Recommended Auxiliary Bus Configuration

Soundtoys recommends using Little Plate on an auxiliary bus with Mix set to 100% wet.

1. Insert Little Plate on an auxiliary or effects return channel.
2. Set the Mix control to 100% wet.
3. Send audio from individual tracks to the auxiliary channel.
4. Adjust the send levels to determine how much of each instrument enters the reverberation.
5. Adjust the auxiliary return level to control the overall reverberation balance. This approach follows the traditional workflow used with hardware plate reverbs.

[!TIP] When using Little Plate on an auxiliary send/return, set Mix to 100% wet and control the reverb amount using the send and return levels in your DAW.

Using Little Plate as an Insert

Little Plate can also be inserted directly onto an individual audio track. For this purpose, Soundtoys designed a Mix control with behavior that differs from a conventional linear wet/dry crossfade. When increasing Mix from 0%, the control initially increases the reverberation level while making relatively little change to the level of the dry signal. This resembles gradually raising a reverb return fader on a mixing console. Once Mix passes approximately 70%, the dry signal begins decreasing more rapidly and smoothly. At 100% wet, the dry signal has been completely removed from the output. This design allows the user to introduce increasing amounts of reverb without immediately reducing the original signal level.

Parameter Lock

Soundtoys plug-ins include a Parameter Lock function that can prevent selected parameter values from changing when presets are loaded. This is particularly useful for the Mix parameter because most Little Plate factory presets use a fully wet setting. If Little Plate is being used as an insert, switching presets could otherwise change the desired wet/dry balance.

How to Lock a Parameter

Platform	Shortcut
macOS	Control + Option + Click on the parameter
Windows	Control + Alt + Click on the parameter
A locked parameter is displayed in red.
While locked, its value remains unchanged when different presets are selected.

[!TIP] Lock the Mix parameter at your desired setting before browsing presets. This lets you audition different reverberation presets without repeatedly adjusting the wet/dry balance.