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RMI Sonic Spark, Clean Boost, and Classic Boost Reviews

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RMI Sonic Spark, Clean Boost, and Classic Boost Reviews

RMI Sonic Spark, Clean Boost, and Classic Boost Reviews

In the not too distant past, Bass Musician Magazine featured a review of the RMI Basswitch; a fully featured and beautifully executed preamp/DI pedal that provides a variety of solutions for bassists, and some slick features that have rightfully earned it the “swiss army knife for bass players” title. More recently, they added a line of smaller pedals to their roster; each designed to provide a specific flavor of EQ and boost options. The RMI Clean Boost, Classic Boost, and Sonic Spark offer up some very usable tonal options, and share the exceptionally robust build quality and design aesthetic that we loved about the RMI Basswitch. We had an opportunity to put the new RMI pedals through their paces, and they did not disappoint.

RMI Clean Boost

Like all the RMI pedals, the Classic Boost offers a wide range of tones available via the 3 band EQ and the gain control of the pedal, and it was apparent to me that the Clean Boost is the most ‘middle of the road’ of the 3, tonally speaking. There is a neutrality and transparency to its tone that really helps to push forward the native sound of your bass. My first impression was that it had less impact on my tone than I felt I was wanting (it is an ‘effect’ after all), but after playing around and gigging with it, I realized that its clean, transparent gain is actually ideal for my needs. It stayed out of the way of my instrument and offered exactly what it advertised: “clean boost”. Even with the gain bumped up and the EQ controls boosted a little, the Clean Boost retained the fat glassy tone of my active 5 string jazz, the woody thump of my flatwound strung P bass, and the midrange complexity of my chambered 6 string. Whereas the other RMI pedals imparted more of their ‘thing’ to my signal chain, the Clean Boost allowed me to keep the sound and feel of my instrument intact, while pushing my signal chain and the front end of my preamp a little harder. One application I really thought the clean boost excelled at was toggling on and off for fingerstyle and slap sections in a song. It allowed me to dig in while playing fingerstyle, and then switch to a hotter/super responsive and dynamic slap tone that called for a lighter touch. I could see this pedal being an excellent choice for someone looking for the kind of boost pedal that preserves the instruments tone, and just offers more of it.

RMI Classic Boost

Up next is the Classic Boost, which, according to RMI is designed to benefit passive or ‘classic’ P/JJ/PJ style instruments. Much like the Clean Boost, the Classic Boost serves up great tone and noise free gain, and also preserves the sound of your instrument.   Where this pedal differs from the Clean Boost, is that it has a little more shape to its tone profile, which again is designed to complement passive or traditional style basses. In my testing I found the Classic Boost to perform as expected. Not quite as glassy or wide as the Clean Boost, the Classic Boost is a bit more ‘in the box’ so to speak. It seems to have less extension on the top and bottom end of the frequency range, and I felt that it helped pocket the sound of my P bass even more effectively than the Clean Boost. Without getting too far into the realm of subjectivity, I would say that the Classic Boost helped focus the midrange on my Fender style instruments.   Like the Clean Boost though, the EQ is powerful and super usable, and an array of legit tones are available. Suffice to say, this is the one that really shines if you tend to stick with Fender or MusicMan style basses.

RMI Sonic Spark

This is the hardest of the three RMI pedals to define. I’ll start with RMI’s product description of the Sonic Spark, which is that of a “harmonic overtone generator”. Instead of a 3 band EQ, the Sonic Spark offers controls for: Gain, Enhance, Intensity and a Deep/Bright blend for optimal tonal tweaking. Firing up the Sonic Spark, I was immediately rewarded with what I would call “tube-like bigness”. Plugged into a rig that I consider very clean and dry, the Sonic Spark spoke with a rich, overtone-laden voice that seemed to accentuate the entire range of the instrument. At higher gain levels, the pedal offers creamy grit, but at lower gain levels, I found the Sonic Spark imparted a hefty weight and thickness to the sound that I can only describe as “tubey”. I had a great time exploring the range of the pedal, especially playing with the deep/bright knob, which serves as a global EQ for shaping tone in those general directions. I was able to find a handful of great “always on” settings, and some sweet solo/boost type settings as well. When really pushed, the Sonic Spark dishes out its fair share of snarl too, which, while not my thing, is undeniably fun. Best of all, it sounds authentic, and has a dynamic feel that really resembles the response of a tube power section.

What else is noteworthy about these RMI pedals? Well, for starters, the componentry in these pedals are second to none. Gold plated relays, loss-free silent footswitches, ultra smooth taper pots, and a discrete JFET input stage all contribute to a smooth operating effect with ultra low noise operation (110db “with very little noise”). Another cool feature of the RMI pedals is their 18V internal power supply. The pedals will accept any 9-15 volt AC or DC power supply, but internally, the voltage is rectified up to 18V, for better headroom. This offers some nice flexibility for pedalboard users, who are constantly trying to juggle the available power channels on units like the Voodoo Labs pedal power 2 and similar isolated power supply units.

There really isn’t anything to dislike about these pedals. Anything I could potentially complain about would be subjective at best, and most certainly a nitpick. For my purposes they did exactly what they’re designed to do, and they did it well. RMI gets extra points for: 1. top mounted jacks (pet peeve alert: wasted space on a pedal board from patch cable jacks protruding from the sides of pedals), and 2. The slight overhang of the faceplate, offering a small degree of additional protection at jack insertion points. I also dug the mellow vibe of the soft blue LED light to indicate that the pedal was engaged.

These RMI pedals offer a lot of usable tone shaping for bassists looking to craft their tone in simple yet sophisticated ways.   The Clean and Classic Boost sell for $259, while the Sonic Spark sells for $299. Not exactly cheap, but well worth the price of admission if you’re looking for some very savvy EQ and tone shaping options in an exquisitely well designed and constructed pedal. Head over to for more information.

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