MP Custom FX is a boutique effects pedal builder based in Belgrade, Serbia, run by designer Milos Popovic. The company builds hand-wired, largely analogue guitar and bass pedals based on original in-house schematics, often mixing germanium and silicon circuitry across its designs.

The lineup spans overdrive and distortion in the Gainiac series (including the Gainiac Plus and Gainiac XL), modulation in the Voodoo Vibe and Micro Vibe, the Modulus modulated analog delay, and the Whole Wah Story filter/wah pedal. MP Custom FX also builds multi-effect enclosures combining drive, delay, and boost circuits, and offers custom graphic finishes on request.

The brand is primarily sold direct through its Reverb shop rather than through traditional retail, and has built a small international following among players looking for handmade, affordably priced boutique pedals.

MP Custom FX has 2 products cataloged on Equipboard, including Overdrive Effects Pedals. Their gear is featured by 1 artist, with the strongest followings in Electronic, Rock, and Metal. Notable users include Henning Pauly.