Lunatic Audio Rocket Fuel

Rocket Fuel’s X/Y pad can act as a macro control, modulating multiple parameters, and can itself be modulated by the LFOs.

Looking for a new plug‑in to fuel your creative endeavours?

Lunatic Audio obviously have a thing for creative multi‑effects. I reviewed their impressive Narcotic plug‑in back in SOS May 2022 and I’ve made regular use of it since, whenever I’ve needed to add a bit of sonic magic to a sound. Launched at a lower price and with what, at first sight, appears to be a somewhat more straightforward GUI, Rocket Fuel covers similar territory: you get a user‑configurable multi‑effects chain and a huge range of parameter modulation options that combine to provide almost endless creative ways to process a sound source.

Three Screens

Rocket Fuel doesn’t hide its processing potential from the user, but Lunatic Audio have done a pretty good job of organising what’s quite a deep feature set into three main screens: an X/Y pad page, an effects chain/modulators page, and a modulation matrix page. These are accessed using three buttons at the top of the GUI and whichever is selected fills the bulk of the (resizeable) window, while the ever‑present panel on the right contains the preset system, macro controls for the X/Y pad, and the main input, output, mix (wet/dry balance) and filter controls. The last of these targets Rocket Fuel’s processing to a specific frequency range; all other frequencies pass through unprocessed.

Rocket Fuel’s X/Y pad is a familiar modulation concept — having assigned parameters to the X or Y axis of the pad elsewhere in the GUI, you can manually apply modulation by moving the node control. You can also modulate the X and Y axis values around the node’s position using any of four LFO sources, of which more below.

The FX Chain & Modulators page is where the bulk of the sound design takes place. The chain is constructed by combining any of Rocket Fuel’s nine effects modules (Chorus, Compressor, Delay, Distortion, Filter, Limiter, Phaser, Reverb and Utility) in the upper part of the page. Note that most of these effects can only be used once in a given chain, but you do get two instances of the Filter and Utility modules. The module order can be changed by dragging and dropping.

The FX Chain & Modulators page lets you build your effects chain and easily link modulation targets to sources.

Each module has a compact control set that provides plenty of flexibility, and every control can be modulated if you wish. There’s little point providing a full run‑down here, but there are a few observations worth highlighting. For example, the Utility module provides pan, gain and stereo width control — modulating pan and volume strikes me as being a more ‘creative’ endeavour than the term ‘utility’ might suggest, and it does these jobs with ease. All the modules are well specified, but the Filter and Distortion modules are worthy of particular attention. In addition to their more obvious controls, the former offers a huge number of underlying filter types (chosen using a drop‑down menu in the mini filter curve display), while the latter includes an impressive range of distortion types, spanning everything from soft or tube‑driven overdrive, through to full‑on gnarly fuzz and bit‑crushing. The Delay is also very flexible, with a filter, ping‑pong options, and full control over left/right timing.

Lunatic have done a great job of easing you into the sound‑design process by offering preset systems that work at every level of the plug‑in. As well as global presets, effects chain presets and modulation presets (all available via the right‑side panel), every effects module also has its own presets and, as I’ll explore in more detail shortly, the four LFOs also have a dedicated preset system of envelopes/curves. Perhaps my only minor gripe (which I imagine could be addressed pretty easily) is the lack of some instrument‑based categories among the global presets. This is something that’s present in Narcotic, and I’ve found them really useful when auditioning presets for a particular type of source sound, such as drums, bass or vocals.

Multiple parameters can be linked to a single modulation source, and individual parameters can be modulated by multiple sources.

All Mod Cons

Not only can pretty much every parameter in a Rocket Fuel signal chain can be modulated, but multiple parameters can be linked to a single modulation source, and individual parameters can be modulated by multiple sources. So whether you want the most subtle of sonic motions or full‑on audio mayhem, the plug‑in’s engine lets you create it.

After direct modulation through the X/Y pad, the FX Chain & Modulators page’s four colour‑coded LFO modulators will probably cater for the bulk of your initial modulation assignments. To link an LFO to a parameter, you simply drag from the colour‑coded ‘+’ button and drop it on the target parameter in the upper effects chain panel. A modulation Depth control (also colour‑coded) pops open above the target parameter to allow you do dial in the required modulation relationship between the LFO source and the target parameter; multiple Depth controls will appear if the parameter is the target of more than one modulation source. If you move away from the parameter, this pop‑up control disappears but will reappear again whenever you hover the mouse over it. You can also drop an LFO assignment onto the controls of the right‑side panel, including the X/Y axis controls. All in all, it’s a delightfully simple and very intuitive approach to modulation assignment.

The Modulation Matrix page provides deeper editing options for your modulation settings.

The four LFOs are identically specified, each coming with an individual Rate control that can be toggled between specifying Hertz or tempo‑sync’ed timing. You can draw your own curves using a number of different brush types, and can specify both a horizontal and vertical grid resolution to assist in that process. The LFO preset collection is well stocked, categorised into useful types such as Basic (waveforms), Envelopes, Gated and Grooves. You can add your own categories and user‑created curves.

Finally, if you wish to get even more detailed when customising your modulation settings, the Modulation Matrix page provides a full list of all the active modulation assignments in the current Rocket Fuel instance. As this follows a fairly conventional format, it’s relatively easy to navigate and provides plenty of options for deep adjustment over how any modulation source/target relationship is configured.

Playing The Fuel

Applying a little (or a lot!) of Rocket Fuel to a range of audio sources is a lot of fun. The most obvious candidates are sustained synth‑based sounds, and the potential to bring even the most timid pad sound out of its sonic shell is considerable. Maybe some cool filter‑based processing or a dollop of gritty drive, or perhaps some tempo‑sync’ed volume modulation to create rhythmic or pulsing effects... there are lots of ways to bring such sounds alive.

With more complex starting points, such as a bass line, a rhythmic guitar part, a sung vocal or a drum loop, it’s possible to have too much of a good thing! In these cases, unless you’re seeking to create an obvious spot‑effect, I’d suggest you have a better chance of achieving satisfying results if you confine yourself to a signal chain with just one or two modules (there are some suitable starting points in the FX Chain’s Simple preset category), lower the Mix value, or focus the processing on a specific frequency range using the filter controls in the right‑side panel. Indeed, it’s worth stating that while Rocket Fuel can do ‘complex and creative’ with ease, if you narrow your options down a little in these ways, it’s also very capable of subtlety. If all you need to do is gently coax a little extra movement from a sound, Rocket Fuel can do just that.

Multi‑effects, Multi‑choice!

When it comes to creative multi‑effects, we’re utterly spoiled for choice today. In SOS we’ve reviewed various options in recent years, including (to name just a few) Output’s Movement, Sugar Bytes’ Turnado and Effectrix, Baby Audio’s Transit, and UJAM’s Finisher Dynamo, and they all provide viable alternatives to Rocket Fuel. Each has specific strengths and they range considerably in price and complexity, so there should be something among them that will be a good fit for almost any type of user. In terms of the creative processing options it provides, Rocket Fuel can be considered a strong competitor for all of the above.

But Rocket Fuel’s biggest direct competition is arguably Lunatic Audio’s other flagship product, Narcotic. Narcotic is a creative marvel that offers a wider selection of effects types. It’s completely bonkers (in a good way!) and very addictive. In contrast, Rocket Fuel boasts more modulation sources and perhaps supports more logical (conventional?) workflows. It too is very creative, but in a more ‘considered’ fashion that might appeal to different users — indeed, if this is your first foray into the world of creative multi‑effects plug‑ins, it would probably be the more accessible starting point. Either way, both deliver great results. Whether you’re a pop producer or electronic musician looking to up your ear‑candy quotient, or a media composer looking for a fresh sound‑design tool, you could do a lot worse than power those ambitions with a little Rocket Fuel.