Doing it backwards: Output Sounds REV reviewed

Sounds played backwards are eerie and evocative. But setting up a whole keyboard layout of backward sounds on your sampler can be time-consuming and tricky. That’s the inspiration for Rev, a sample library from relative newcomers Output Sounds, which aims to take the work out of it and let you get creative. Here's our full review.
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Sounds played backwards are eerie and evocative. But setting up a whole keyboard layout of backward sounds on your sampler can be time-consuming and tricky. You may have to reverse the playback direction of dozens of samples and then spend half an hour fine-tuning the envelope shapes so that the note on every key will be the same length.

That’s the inspiration for Rev, a sample library from relative newcomers Output Sounds. In Rev, every key produces the same note length, so you can play a block chord of backward sounds and all the notes will reliably end at the same moment. Better still, the notes know the tempo of your song, so you can play a reversed chord on beat 4 and it will end on the downbeat of the next bar. But there’s a lot more to Rev than that, including a big bank of exotic loops. Let’s take a closer look.


Rev requires Native Instruments Kontakt soft sampler, or the free Kontakt Player instrument host. The latter is a free download, and I used it for this review. You can dig deeper into sound programming if you have the full version of Kontakt (a separate $399 purchase, and also included in the various versions of Native Instruments’ Komplete bundle). For instance, Rev’s LFO outputs only a square wave, and it can’t be used to modulate filter cutoff—but if you have the full version of Kontakt, you can add your own filter LFO. The limitations of Kontakt Player can become troublesome if you need to change the velocity response or add sound shaping from the modulation wheel, because Rev in that context offers no user editing of those things.

Rev includes four libraries: Instruments, Rises, Loops, and Timed Instruments. Each has a slightly different set of features, but they all have a similar LFO setup (a syncable square wave that can modulate either pitch or amplitude), half a dozen resonant filter modes (lowpass and highpass), and basic ADSR envelopes for amplitude and filter cutoff. The Instruments and Timed Instruments layer two samples, but of course you can layer as many in Kontakt Player as your RAM and CPU will allow.

Each instrument has seven or eight effects that can be edited in basic ways. In the Instruments and Timed Instruments groups, each of the two layers has its own set of effects, and there’s a third global set. Adding things like lo-fi, chorus, and distortion can transform a Rev preset in drastic ways, so the sound design possibilities are deeper than you might think at first glance. Individual effects can be switched on or off from MIDI keys in the bottom octave. Kontakt Player’s parameters can also be automated from the host program, but being able to gate the effects in real time is a neat extra.

There’s no owner’s manual, but most functions are explained by a help panel that pops up when you click the “?” button (see Figure 1). The online video demonstrations are also helpful. Some of the presets contain as much as 200MB of sample data, so loading can take a few seconds.


The Instruments library offers a dozen folders of presets with names like “Pads Complex,” “Pulses,” “Swells,” “Plucked,” and “Stutter One-Shots.” Each of these folders has dozens of presets; in all, there are hundreds to choose from. You can load a different multisample into either layer if you like, and here your choices are a bit narrower: There are only 27 multisamples in all. They’re thoughtfully chosen, however—everything from acoustic and electric piano through struck bowls, noisy harmonics, and ethnic percussion.

You’ll want to spend some time exploring the multisamples. Some of them are very different from one key to the next, and many have three or more velocity cross-switch zones. But that’s just the start of the fun. Each layer can be played dry, wet (a rather prominent sampled reverb), forward, or looped as a pad. The two layers share a sample start offset parameter, with which you can make tight notes or long smooth swells.
The setup in the Timed Instruments library is very similar, except that the sample start offset slider is replaced by a selector for quarter-note, half-note, or whole-note length.


My favorite part of Rev is the Loops library. There are only 15 presets, but each one maps two dozen different loops to the keyboard. Some of the presets are percussive, and others are made up of performances using tones (such as piano or struck bowls) played backwards. The lower two octaves of the keyboard can be used to transpose the loop up or down. You can hold several loops at once for layered madness, but this library has only one voice layer, not two. Be sure to try out all of the keys in the preset, because you’ll find quite a variety of textures.

Half-speed/normal/double-speed switching is included. Depending on the source material, there may be small audible artifacts when you change the speed or pitch, but these are not usually bothersome, and with conventional DSP-based granular time-stretching, they’re more or less inevitable. With a loop that includes a ride cymbal, for example, lowering the pitch will add clicky double attacks to a few notes, and speeding it up more than a few half-steps will blur the attacks, turning the cymbal into a wash. But try playing one of the acoustic piano loops transposed down an octave at half-speed for some instant Brian Eno-style ambient music. Total bliss!

The loops sync to your DAW’s transport, naturally, and I heard no artifacts during real-time tempo changes (other than a bit of crackling when REV’s delay effect is being applied, and that’s more or less inevitable).


The Rises library seems well suited to movie soundtracks and dance music. It provides 72 backward rises—mainly cymbals, orchestral clusters, and machine noises. The menu organizes these by rhythmic length (from one quarter of a bar up to four bars), so you can quantize your note to a rhythm value in your DAW and be confident that the rise will end exactly where you want it to. Using the half-speed/double-speed switch, the actual tempo length ranges from eighth-notes to eight bars.


It’s not often that a new company hits the ground running with a sound library that attracts so much notice, but Rev has been getting rave reviews, and deservedly so. It’s not a do-everything library, but it’s not designed to be. Rather, it can be used to spice up almost any production, adding color where color is needed. The user interface is simple but well designed, giving you the controls you’re most likely to want. Owners of the full version of the Kontakt soft sampler will be able to coax more from Rev, but even with Kontakt Player, you won’t be disappointed. If you need fresh sounds in your productions, Rev is a set of colors you should definitely have on your palette.

PROS: Fresh, expressive, and unique sounds. Loop content is a cool bonus.

CONS: Full sound programming not possible with the free Kontakt Player host.

Bottom Line: Rev sounds terrific. It’s a specialty item, but there’s nothing else like it.

$199 |