Whitestone Audio is a boutique American manufacturer dedicated to creating innovative analog processing tools that deliver subtle, musical enhancement for recording, mixing, and mastering professionals. Founded by Dave Rosen and mastering engineer Kim Rosen, Whitestone was born from the pursuit of a unique mastering tool capable of adding depth, dimension, harmonic richness, and sonic polish without compromising the integrity of the original mix. Best known for the acclaimed P331 Tube Loading Amplifier series, Whitestone products are designed to provide engineers with precise, repeatable control over analog coloration, allowing them to elevate recordings with everything from delicate refinement to bold harmonic character. Combining high-fidelity tube circuitry, meticulous craftsmanship, and a mastering-first design philosophy, Whitestone Audio has earned the trust of discerning engineers seeking premium analog tools that enhance music in a natural, elegant, and musically inspiring way.