RhFp Electronics Has Built An Original And Impressive MOSFET Drive With The Mosphoros

3 different gain controls combine to allow unique tone shaping and a wide range of gain.

Another Overdrive Pedal? Not Quite

For years I have had overdrive fatigue. I reviewed dozens of different boutique takes on a Klon Centaur, TS8, or BluesBreaker, to the point of struggling to differentiate much. This is a contributing factor to the growing infrequency of pedal reviews, and particularly less coverage of gain pedals. Luckily for me, the Mosphoros pedal is a lot more interesting, original, and capable than the typical boutique drives that came across my desk over the past 7 years.

Originating in Switzerland, the Mosphoros is one of the flagship pedals for RhPF Electronics. True to the description on the webpage, this pedal does have excellent range across the boost-fuzz spectrum of gain. This is accomplished through a pretty cool set of controls. There are two “tone” knobs, but they really are more gain knobs than your standard EQ. These two knobs shape not just the low and high end, but actually control where the gain is applied. Specifically, the bass and treble add gain below 1 kHz and above 250 kHz. You can use the pedal as a perfect clean both by zeroing out all 3 knobs and just using the level control. The other gain knob, marked drive, is more like a typical preamp, adjusting the bias of the circuit in a way that’s likely more familiar to vintage fuzz players. All 3 of these so-called gain controls are interacting together in the circuit, making for a nearly endless combination of tones unlike your traditional gain-tone-volume stack on most drive pedals.

Demo Time & Final Thoughts

I set up my Quad Cortex Mini to replicate a clean Roland Jazz Chorus and plugged in my custom Moon Guitars Asteroid (single P90) and got right to recording. Right off the bat I was stoked by how much gain was packed into this pedal. I didn’t spend as much time on the boost-ier, clean sounds because I just really loved how amp-like the distortion and break up was from this pedal. It’s got the classic MOSFET sounds in there, but it is operating more like a mini-amp or preamp than other pedals.

As complex as the 3 interacting gain knobs are, this pedal never feels too difficult to operate. At multiple points I just started following my ears, tweaking knobs and balancing volume until I easily found rich sustain and huge, gritty distortion tones. Playing through a single P90 guitar, the touch sensitivity was on full display, as I felt the pedal sort of melted in to my playing style and pick attack along the guitar. The Mosphoros is both brilliantly engineered and stupidly simple, which is perfect for someone who primarily plays big punk rock distortion like myself. More advanced tone tweakers could have a wonderful time dialing in the exact gain amount on the exact frequencies, but you don’t need to do that to enjoy this pedal, or get the best out of it. Mosphoros is unique in that way compared to many other gain pedals I’ve reviewed, which either cater to the ultra knob and control obsessed market, or are highly streamlined and simplified.

The current conversion price has these at about $191 USD, as provided by the RhFP website. I can’t find much fault in that, though admittedly I don’t know how much international shipping may inflate this if you’re purchasing from the US or Canada. But for sub-$200, this is a very versatile, useful, and unique overdrive pedal that sticks out from the crowd of Klones, Screamers, and BluesBreakers that have seen a major drop in sales and overall excitement. Hats off to RhFP Electronics, who have me excited about gain pedals at a time when that’s getting increasingly hard.

Don’t just take my word for it, here’s a great video from Philip Czarnecki showcasing the pedal!