OverTone DSP is a British audio software developer specializing in digital signal processing plugins for mixing, mastering, and recording. Operating as a division of Applied Computer Music Technologies Ltd, the company built a niche reputation for cross-platform support, releasing its tools in VST, VST3, Audio Unit, and AAX formats for Windows, macOS, and Linux — the last of which made the brand a familiar name among Ardour and Linux DAW users.

The catalog focused on emulations of classic studio hardware alongside original analog-modeled designs. Notable plugins include the PTC-2A program EQ and PTM-5A mid-range EQ (inspired by the Pultec EQP-1A and MEQ-5), the FC70 compressor (drawing on the Fairchild 670), the EQ4000 E-series console EQ emulation, and the 500-series-styled EQ500, Dyn500, and RVB500. The AF2-10 and AF2-10M rounded out the EQ line with linear-phase and minimum-phase variants.

OverTone DSP plugins were generally pitched at engineers looking for affordable analog-style processing with low CPU overhead, and the brand was reviewed by outlets such as MusicRadar and discussed across communities like KVR Audio, Gearspace, and Linux Musicians.

Overtone DSP has 3 products cataloged on Equipboard, including EQ Plugins and Compressor Plugins. Their gear is featured by 1 artist, with the strongest followings in Electronic and Pop. Notable users include David Guetta.