AEA Microphones Limited-Edition KU4A Active Supercardioid Ribbon Microphone

Combining the smooth, expressive character of a classic ribbon microphone with the focused response and output of a modern active design, the AEA limited-edition KU4A active supercardioid ribbon microphone brings exceptional versatility to professional recording. Inspired by RCA's legendary KU3A, the KU4A pairs a supercardioid polar pattern with extended high-frequency response and reduced proximity effect, allowing engineers to capture vocals, instruments and high-SPL sources with clarity and control. Its integrated JFET buffer amplifier and custom 1:110 Lehle transformer deliver 12dB more output than the passive KU4, while 24-karat gold accents and a numbered certificate of authenticity distinguish this special edition. Created through a partnership between AEA and the Guitar Center Music Foundation, this Guitar Center Exclusive microphone also supports a broader mission of expanding access to music through instrument grants and donations.

Supercardioid Precision With Classic Ribbon Character

Unlike traditional figure-eight ribbon microphones, the KU4A features a supercardioid polar pattern that provides focused pickup and rejection of unwanted sound from surrounding instruments and room reflections. Its near-field design supports placement approximately 1"–18" from the source, with reduced proximity effect helping maintain a balanced low-frequency response during close-miking. From intimate vocal performances and acoustic instruments to woodwinds and percussion, the KU4A combines the natural midrange and smoothness of a ribbon with an extended top end that brings presence and detail to recordings. With SPL handling exceeding 140dB at 1kHz, it also accommodates demanding sources such as kick drums and amplified instruments.

Active Electronics for Greater Output and Flexibility

Building on the design of the passive KU4, the KU4A incorporates a JFET buffer amplifier and custom 1:110 Lehle transformer to provide 12dB more output. This active circuitry makes the microphone easier to integrate into modern recording setups while preserving the dynamic response and tonal character associated with AEA's ribbon designs. The combination of higher output, controlled directionality and smooth high-frequency response gives engineers greater flexibility when recording a wide range of sources, particularly in environments where microphone placement and isolation are critical.

Limited-Edition Craftsmanship With 24-Karat Gold Accents

Handcrafted at AEA's Pasadena, California, facility, this limited-edition KU4A honors the legacy of the RCA KU3A, a rare unidirectional ribbon microphone originally developed for Hollywood film studios. Distinctive 24-karat gold accents set this version apart, while an individually numbered certificate of authenticity commemorates its limited-edition status. Available exclusively through Guitar Center and its family of brands, the KU4A brings together vintage-inspired microphone engineering, modern active electronics and collectible details in a distinctive professional recording tool.

Supporting Music Education Through the Guitar Center Music Foundation

The limited-edition KU4A was developed through a partnership between AEA and the Guitar Center Music Foundation following the devastating 2025 Los Angeles wildfires. As the Foundation worked to replace instruments and equipment lost in the fires, AEA created this special edition to help support musicians and music programs affected by the disaster. With the initial wildfire relief initiative now complete, a portion of proceeds from the remaining microphones continues to benefit the Foundation's ongoing instrument grant and donation programs. The collaboration reflects a shared commitment to helping schools, nonprofit organizations and music programs provide greater access to instruments and the opportunities that music creates.