Digital Reverb Pedal

Signal Processors > Reverbs

Published April 2023

There are many reverb pedals around, but this box has a few tricks up its sleeve.

While the Cloudburst may be one of Strymon’s smallest pedals, it delivers one of the biggest sounds around! As you might imagine, given that it has been designed to produce ambient reverbs, it’s capable of some impressively long reverb times, yet it still somehow manages to prevent the sound from becoming ‘messy’. It has fewer hidden functions than most Strymon pedals, and it only employs one reverb algorithm — it’s based on a modified version of the Big Sky’s Clouds reverb effect — but don’t let that fool you into thinking that this is a one‑trick pedal, as it does have an extra superpower, which I’ll get around to shortly.

Overview

By way of connectivity, there are only three jacks on the back of the case, but both the in and out jacks are in fact TRS types that can be used for mono or stereo signals. The input can handle signals up to +10dBu in level so, with care, line‑level signals can be accommodated, not just guitars. A recessed toggle switch selects mono, mono‑to‑stereo or stereo modes. The third jack is for connecting an optional TRS expression pedal, a Strymon MiniSwitch or MultiSwitch Plus, or a TRS MIDI connection. The available switch modes are Favourite, Infinite or Freeze; the last of those sustains the current reverb tail indefinitely to create a sort of ‘pad’, over which you can then play without adding to the reverb.

The PSU jack is also on the rear, and a 9V PSU capable of at least 250mA is required (though not included in the price). A Spillover mode, which provides a buffered output, allows the reverb tail of the current preset to fade naturally when bypassing the pedal or when switching to the next preset using a MultiSwitch Plus or MIDI for preset switching (using MIDI there’s access to 300 presets, which are arranged in three banks). With Spillover switched off the pedal has a hard‑wired bypass. A Strymon MultiSwitch Plus can be used to access three presets.

The jacks for the audio input and output are TRS types, and can be configured to receive and send mono or stereo signals.If the control jack is configured for MIDI, using either a Strymon Conduit or MIDI Exp cable, MIDI Program Change messages are supported, while MIDI CC messages can be used to adjust the effect parameters. There’s also a USB‑C port, which can be used for MIDI, but is also used for firmware updates and communication with Strymon’s free Nixie editing software. In expression pedal mode, the pedal can be used to morph between two sets of control knob settings. The setup routine for the pedal involves holding down the footswitch when powering up and then using the various knobs to change modes as described in the manual.

Other user settings include the way the dry signal is treated, which can go via the digital converters or be kept in the analogue domain. There’s also a dry kill mode allowing the Mix knob to be used as an effect level control. The status LED changes colour when setting up to act as a mode indicator.

As with the v2 revisions of the existing Strymon pedal range, the Cloudburst is based on a new ARM processor platform with 32‑bit floating‑point processing (as opposed to the SHARC processors used in the earlier pedals), and it also runs at a higher clock rate. This more powerful CPU allows the pedal to run an enhanced reverb algorithm at the same time as generating the Ensemble effect, of which more shortly. Its JFET front end is taken from that used in the v2 pedals, the aim being to present the guitar with a more amp‑like impedance and to improve playing feel. Audio conversion is at 24‑bit/96kHz.

Head In The Clouds

Most of the rotary controls are self explanatory, but what isn’t immediately obvious is their huge range. Decay goes from a really convincing, tight room‑like ambience up to a lush‑sounding decay that doesn’t quite go to infinity but does get within a couple of metres of it! To my ears, the character of the algorithm changes once the Decay control goes past half way. In the first half it creates a range of conventional but very high‑quality ambiences and reverbs that get progressively larger. Past half way, you get lovely ambient reverbs that get progressively longer and seem somehow to hang in the air, decaying quite slowly, and providing background support without getting in the way. You have to be fairly precise in making adjustments here, as a little movement goes a long way.

The pre‑delay can also be set much longer than on a normal reverb. It’s almost as if you have a separate delay pedal in series with the Cloudburst. Pre‑delay also works well with short reverb decay times to create a classic slap‑back, rockabilly delay effect. Short reverb settings also produce a really believable room ambience that works a treat on electric guitar. Tone seems to act like a tilt control, trimming away the highs when moved anticlockwise, to create a warm, dark reverb; or boosting the highs when turned clockwise. Mod brings in pitch modulation and controls rate and depth up to its mid position, after which the depth stays the same but the modulation gets faster. Around half way or just below, it adds an attractive fluidity to the reverb.

The real secret weapon is the three‑way Ensemble switch at the top of the panel... It brings in some additional harmonics that sound almost synth‑like.

Mix does just as you’d expect, going from 100% dry to 100% wet, unless set up in Dry Kill mode, but the real secret weapon is the three‑way Ensemble switch at the top of the panel, which can be off or set to one of two intensities. This isn’t based on conventional ensemble effects that use multi‑layered chorus and so on, but rather it brings in some additional harmonics that sound almost synth‑like. There are hints of octave‑up and an increase in harmonic density and richness, but this is no conventional shimmer reverb either. Apparently the effect is achieved by splitting the signal into 48 frequency bands and then new harmonics and partials are generated based on these frequencies. (The closest technology I can think of is Roland’s HRM harmonic modelling, used in the Boss SY‑series guitar synths and VG guitar pedals.)

With the reverb decay set to be fairly short, the ensemble sound reminds me of my long‑gone Roland GR‑300 guitar synth, although with the GR‑300 you had to add your own reverb. Extend the reverb length slightly, and the synth‑like sound takes on a natural decay. Add some volume swells from a volume pedal, your guitar’s volume control or a ‘slow attack’ pedal, such as the Electro‑Harmonix Attack Decay, and you could easily believe you were listening to a synth rather than a guitar. As the newly generated sounds are based on the input signal, the effect is very responsive to playing dynamics, style and pickup selection. At longer reverb times, the effect is like a more complex version of a shimmer reverb, adding a strings‑like backdrop to the input.

Summary

The Cloudburst is billed as an ‘ambient reverb pedal’ so definitely targets (and should definitely appeal to) those who make ambient‑style music, though I do want to stress that it’s not limited to that; its shorter reverbs and ambiences are also seriously impressive. The pedal can of course be used to process any sound source, though I’m guessing that guitar players are still the prime market. If you love long, dense reverb tails that seem to hang in the air like smoke, then you are going to find it difficult to resist. I tried to replicate its ‘reverb as a background sound’ effect using other reverb pedals I already own, but none of them came close. Adding the Ensemble effect opens up a whole new sonic landscape and works so well that I’m hoping Strymon might have plans to build something more guitar‑synth‑like, by combining their take on harmonic resynthesis with attack shaping and envelope filtering.

Though a little less costly than most of Strymon’s pedals, the Cloudburst is still outside of the impulse buy range for most people, but I feel that it is well worth the investment, especially if your music has ambient or cinematic leanings. The review unit had to go elsewhere very quickly, and I had to nail my credit card to the table in an attempt to prevent me ordering one. Unfortunately, my hammering was inadequate: the nail fell out, and a new one is on its way!

Pros

Excellent range of reverbs, from small room ambiences right up to full‑on ambient reverb backdrops.
Pristine sound quality.
Very manageable set of controls.

Cons

Extra switches or adaptors needed to switch patches while performing.
PSU not included.

Summary

A reverb and delay like no other, and not just for guitarists, the Cloudburst conjures up some original and engaging effects, as well as catering for more conventional ambiences.