ARREL Audio is an Italian manufacturer of professional audio equipment based in Rome, founded by a team with backgrounds in audio engineering, electronic design, and academic research. One of its co-founders, Livio Argentini, has been working in Italian analog audio design since the 1950s, and the company positions itself at the intersection of classic analog circuit design and modern digital technology.

The catalog is organized into several product lines. The 500 Series covers mic/line preamplifiers, parametric equalizers, compressors, and mid-side processors; the Classic Line (CL) and Elite Line (EL) offer channel strips, summing mixers, and equalizers for studio use; the Monster Line (ML) targets mastering with high-end summing consoles and EQs such as the ML-116; and the 600 Line includes guitar and bass splitters. ARREL also produces a range of Eurorack modules, including the ER-100 stereo summing mixer, the ER-140 SUMMUTE, and the ER-150 HERCULES, which bring the company's transformer-coupled, high-fidelity circuit approach into the modular format.

The brand is known among mastering and mixing engineers for its emphasis on transformer-driven outputs and carefully matched analog circuitry. Endorsers listed by the company include session drummers Russ Miller and Matt Bissonette, percussionist Luis Conte, and mastering engineer Pete Doell.

ARREL Audio has 4 products cataloged on Equipboard, including Effects Processors, Effects Pedal Accessories, and Preamps. Their gear is featured by 2 artists, with the strongest followings in Rock, Pop, and Electronic. Notable users include Matt Bissonette and Luca Pretolesi.