{"product_id":"aea-ku4","title":"AEA KU4","description":"\u003cdiv lang=\"en\"\u003e\n  \u003cp\u003e\u003cstrong\u003eAEA KU4\u003c\/strong\u003e is a passive supercardioid ribbon microphone — the only ribbon microphone with a supercardioid polar pattern in current serial production. It is based on the RCA KU3A (catalog number M-10001), a unidirectional ribbon microphone from the 1950s designed for overhead boom use in Hollywood motion picture studios, of which fewer than 600 units were ever built. The KU4 achieves its supercardioid pattern through a precision-milled aluminum acoustic labyrinth that delays rear-arriving sound to produce phase cancellation of the rear lobe — no English cow hair as in the original RCA. The 1.8-micron ribbon at 28,6 mm × 2.1 mm from NOS RCA material is substantially shorter and narrower than the Big Ribbon used across the R44 series — closer in size to the RCA 77 family, but with a fixed pattern and a more natural-sounding unidirectional response.\u003c\/p\u003e\n\n  \u003ch3\u003eSupercardioid Ribbon — Upper-Mid Presence, No Resonances, No Bleed\u003c\/h3\u003e\n  \u003cp\u003eThe shorter ribbon element produces a pronounced upper-midrange accent — the KU4 is the brightest microphone in the AEA lineup. That midrange presence makes vocals, strings, and woodwinds read clearly in a mix without EQ, delivering ribbon smoothness without condenser harshness. Reduced proximity effect compared to the Big Ribbon designs allows close miking at 1–18 inches without the low-frequency buildup that makes most ribbon microphones unpredictable at this range. The suppressed rear lobe eliminates lateral bleed from adjacent instruments and early reflections off low ceilings, making the KU4 the practical ribbon choice for live tracking sessions and acoustically untreated spaces. Frequency response extends above 40 kHz with no upper-midrange resonances that are typical of large-diaphragm condenser capsules. The pole piece and ribbon assembly are field-tech replaceable without sending the unit to a service center.\u003c\/p\u003e\n\n  \u003ch3\u003ePassive Circuit and Preamp Requirements\u003c\/h3\u003e\n  \u003cp\u003eThe KU4 requires no phantom power — 48 V is not recommended. Sensitivity of 2.8 mV\/Pa (–51 dBV) and 300 Ω nominal output impedance require a preamp with at least 60 dB of gain and input impedance above 1.2 kΩ — the same requirements as the passive R84 and R44 series. The grille basket and yoke are interchangeable with an original RCA KU3A. The microphone ships with a 1.5-meter captive cable, a custom storage\/shipping case, and a stand adapter; the cushion mount yoke is derived from the R44 series design.\u003c\/p\u003e\n\n  \u003ch3\u003eKEY FEATURES\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eThe only passive supercardioid ribbon microphone in serial production\u003c\/li\u003e\n    \u003cli\u003ePolar pattern: supercardioid — precision-milled aluminum acoustic labyrinth suppresses rear lobe\u003c\/li\u003e\n    \u003cli\u003eBased on RCA KU3A — fewer than 600 original units ever built\u003c\/li\u003e\n    \u003cli\u003e1.8-micron aluminum ribbon — 28.6 mm × 2.1 mm (NOS RCA material)\u003c\/li\u003e\n    \u003cli\u003eShorter ribbon: more upper-mid presence and brighter tonal character than Big Ribbon designs\u003c\/li\u003e\n    \u003cli\u003eReduced proximity effect — close miking at 1–18 inches without low-end excess\u003c\/li\u003e\n    \u003cli\u003eResponse to above 40 kHz, no upper-midrange resonances\u003c\/li\u003e\n    \u003cli\u003eMax SPL: 140+ dB (1% THD harmonic distortion \u0026gt;200 Hz)\u003c\/li\u003e\n    \u003cli\u003eSensitivity: 2.8 mV\/Pa (–51 dBV) into unloaded circuit\u003c\/li\u003e\n    \u003cli\u003eOutput impedance: 300 Ω nominal\u003c\/li\u003e\n    \u003cli\u003eRecommended load impedance: ≥1.2 kΩ\u003c\/li\u003e\n    \u003cli\u003ePhantom power: not required or recommended\u003c\/li\u003e\n    \u003cli\u003eField-tech replaceable pole piece and ribbon assembly\u003c\/li\u003e\n    \u003cli\u003eGrille basket and yoke interchangeable with original RCA KU3A\u003c\/li\u003e\n    \u003cli\u003e1.5 m captive cable, XLR-3M; storage case and stand adapter included\u003c\/li\u003e\n    \u003cli\u003eDimensions: 324 mm (H) × 117 mm (W) × 95 mm (D); weight: 2.15 kg with cable\u003c\/li\u003e\n    \u003cli\u003eHandmade in Pasadena, California, USA\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch3\u003eTECHNICAL SPECIFICATIONS\u003c\/h3\u003e\n  \u003cul\u003e\n    \u003cli\u003eOperating principle: pressure gradient transducer (passive)\u003c\/li\u003e\n    \u003cli\u003ePolar pattern: supercardioid\u003c\/li\u003e\n    \u003cli\u003eFrequency range: \u0026lt;30 Hz – \u0026gt;20 kHz (extended to \u0026gt;40 kHz)\u003c\/li\u003e\n    \u003cli\u003eMax SPL: 140+ dB (1% THD \u0026gt;200 Hz)\u003c\/li\u003e\n    \u003cli\u003eSensitivity: 2.8 mV\/Pa (–51 dBV) into unloaded circuit\u003c\/li\u003e\n    \u003cli\u003eOutput impedance: 300 Ω nominal\u003c\/li\u003e\n    \u003cli\u003eRecommended load impedance: ≥1.2 kΩ\u003c\/li\u003e\n    \u003cli\u003ePhantom power: not required or recommended\u003c\/li\u003e\n    \u003cli\u003ePolarity: Pin 2 + for positive pressure at front\u003c\/li\u003e\n    \u003cli\u003eRibbon thickness: 1.8 µm; width: 2.1 mm; length: 28.6 mm\u003c\/li\u003e\n    \u003cli\u003eRibbon material: corrugated aluminum (NOS RCA material)\u003c\/li\u003e\n    \u003cli\u003eConnector: XLR-3M on 1.5 m captive cable\u003c\/li\u003e\n    \u003cli\u003eDimensions: 324 mm (H) × 117 mm (W) × 95 mm (D)\u003c\/li\u003e\n    \u003cli\u003eWeight: 2.15 kg (with cable)\u003c\/li\u003e\n    \u003cli\u003eMade in: USA (Pasadena, CA)\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e","brand":"AEA","offers":[{"title":"Default Title","offer_id":54014124851537,"sku":"27623","price":0.0,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8741\/0769\/files\/AEAKU4.jpg?v=1781105346","url":"https:\/\/wrdtunes.com\/fr-fr\/products\/aea-ku4","provider":"Wired Tunes","version":"1.0","type":"link"}