Xploration • Curation • Recommendation
OPFXS unleashes ingenious analog Gain Box - Boost / Overdrive / Fuzz / Distortion - with some digital controls and Presets
Key Points
OPFXS Gain Box — all-analog sound generation and routing with some digital controls and 3 Presets. Controls: Level (digital), Filter 1k→16k (digital), Dry Level (analog), Fuzz/Overdrive/Distortion Masters (analog), Preset LEDs I–III, channel buttons FZ, OD, DS, DRY, Series/Parallel LED, Preset footswitch (hold to save), Bypass footswitch (hold to flip modes). Secondary functions via holding DS+DRY.
Two modes — Series (Dry+Overdrive into Fuzz+Distortion) and Parallel (each stacked). Presets do not save analog levels (Dry, Fuzz, Overdrive, Distortion) but save channel selections, digital controls and Series/Parallel status.
Described as reminiscent of Empress Multidrive but compact. As of 2026-07-13, price was £217 via OPFXS Webstore.
I’m known for my love of Multi-Gain boxes - and this is another great innovation in that area - a really smartly engineered gain machine - with all-analog sound generation and signal routing, but with some digital controls, and 3 Presets onboard.
You have two main Operational Modes - Series and Parallel, where the Series Mode is essentially Dry + Overdrive into Fuzz + Distortion, and Parallel is each of them piled on top of the other!
Controls - Level [digital], Filter : 1k > 16k [digital], Dry Level [analog], Fuzz Master [analog], Overdrive Master [analog], Distortion Master [analog], Preset LEDs I-III, Channel Select Buttons : FZ, OD, DS, DRY, Series / Parallel Mode LED, Preset Footswitch [hold to Save], Bypass Footswitch [hold to flip Series / Parallel Modes].
There are a couple of extra secondary controls - achieved by holding down the DS and DRY buttons, otherwise all the controls are pretty well surfaced and instantly accessible.
The Fuzz, Overdrive and Distortion Levels are Master controls presumably - which blend Volume and Gain. And the essence of this pedal is selecting and blending those channels and adjusting the output to taste. It’s a little reminiscent of my Empress Multidrive - but in a much neater more compact format - with overall fewer controls, but in some ways more granularity!
Note that Presets don’t preserve any of the ’Analog’ controls - i.e. the Dry, Fuzz, Overdrive and Distortion Levels, but they to save the Channel Selections, Digital Controls, and Series / Parallel Mode status!
This is exactly the kind of gain pedal I gravitate towards, and I will for sure be coming for one of these! I love variously mixing up Fuzz with Overdrive and Distortion - which is something I got very accustomed to on my Empress Multidrive. This is like an evolved compact edition of that for me in many ways!
The Gain Box is just €250 (£217) on the OPFXS Webstore - and I will definitely be coming for one of these early next month. Alas my dance card is full for this month! I have too many other commitments for May already - otherwise I would already have pounced on this! Really love what this encapsulates - OPFXS do such smart engineering. I have other pedals from this brand on my wishlist - while this will undoubtedly be my first to land from this Brand!
Demos
