RedTron_400 is a software instrument designed to replicate the classic sound of the Mellotron M400, a keyboard known for its distinctive tape-based playback. The interface is crafted to provide an authentic user experience, featuring six carefully sampled sound types including violins, flute, choir, brass, cello, and string section. Each sound sample is originally eight seconds long, preserving the character of the original instrument's playback.

Users can switch between the traditional playback mode, where samples play for their full length, and a loop mode that allows continuous repetition of the sound. This flexibility enables creative layering and sustained tones that enhance the musical possibilities. RedTron_400 supports layering with independent control over various parameters such as volume, tuning, reverb, delay, pan, octave, note, cutoff, resonance, attack, and release, giving users precise control over their sound design.

The plugin also includes built-in delay and reverb effects with adjustable settings, allowing for further customization and depth. Global controls for volume, tone, and pitch provide easy overall adjustments. Additionally, RedTron_400 can function as a SoundFont player, expanding its utility for musicians looking to incorporate classic Mellotron sounds into their productions with ease.