HRK is a Polish manufacturer of handmade analog recording equipment based in Łódź, founded and run by Bart Hrk. The company specializes in 500 Series modules built around the Colour format (originally developed by DIY Recording Equipment), with a focus on adding analog character, saturation, and harmonic content to digital recordings.

Its catalog includes the MP568C and MPQ568C Colour mic preamps, the ST596 analog harmonics processor and tape emulator, the ST552, the CP554 compressor, the C2584, and the EQ522 equalizer. Many products are sold both as fully assembled units and as DIY kits, and the modules are designed using NOS discrete components and germanium-based circuits in some EQ designs.

HRK has built a following among home and project studio owners looking for affordable analog tone-shaping tools, with reviews appearing in outlets such as MusicTech and Tape Op. Distribution is largely direct through the company's own shop and Reverb, alongside listings at retailers like Guitar Center.

HRK has 3 products cataloged on Equipboard, including Effects Processors.