Sovtek is a brand of vacuum tubes, guitar amplifiers, and effects pedals owned by Mike Matthews's New Sensor Corporation, the parent of Electro-Harmonix. Established at the end of the Cold War, the brand was built around tube manufacturing at Russian factories (notably the Reflektor plant in Saratov), reusing Soviet military-grade production capacity to supply tubes such as the 12AX7, EL84, EL34, 6L6, and 6550 to amp builders including Fender, Marshall, Mesa/Boogie, and Peavey.

Beyond tubes, Sovtek became known for a line of rugged, no-frills guitar amplifiers introduced in the early 1990s, including the MIG-50 and MIG-100 — hybrid Bassman/Marshall-style heads and combos with chassis-mounted tube sockets and utilitarian, military-style cosmetics. The brand is equally famous for the Russian-era Big Muff Pi pedals built for Electro-Harmonix at the Sovtek facility, including the "Civil War," "Green Russian," and "Black Russian" versions, prized for their thick low end and gritty fuzz character.

The Russian-made Big Muffs in particular became staples of alternative, grunge, shoegaze, and stoner-rock rigs, with players such as Thurston Moore and Lee Ranaldo of Sonic Youth associated with the Sovtek-era pedals. Sovtek operates today primarily as a tube brand distributed through Electro-Harmonix's retail channels, while EHX has reissued several of the classic Sovtek-era Big Muff circuits under the Sovtek name.

Sovtek has 5 products cataloged on Equipboard, including Guitar Amplifier Tubes, Guitar Amplifier Heads, and Guitar Amplifier Cabinets. Their gear is featured by 1 artist, with the strongest followings in Rock. Notable users include Dylan Hanwright.