AEA R84A is an active Big Ribbon microphone powered by 48 V phantom — the direct active counterpart to the passive R84. The pill-shaped body, 1.8-micron aluminum ribbon at 59.7 mm × 4.7 mm, 16.5 Hz resonant tuning, and German-made Lehle transformer are identical to the R84. Active JFET electronics — the same topology used in the A440 and the TRP/RPQ preamp series — deliver +12 dB of output over the passive version and a broadband output impedance of 92 Ω, load-independent regardless of the preamp's input impedance. The R84A was previously manufactured under the name A840. Its distinctive 18-karat gold-plated grille basket distinguishes it from the black grille of the passive R84.
Active Electronics and Impedance Stability — Big Ribbon Through Any Signal Chain
A passive Big Ribbon is a 270 Ω nominal source — its tonal balance and output level shift measurably with the input impedance of the connected preamp. A preamp at 1.5 kΩ loads the ribbon differently than the same unit presenting 10 kΩ, altering the low-end character and overall level. The R84A's active JFET buffer and Lehle step-up transformer output at 92 Ω broadband regardless of load, keeping the Big Ribbon's tonal character consistent across any preamp — from a tube La Chapell to a Mackie Onyx. The +12 dB gain over the R84 brings output to condenser-level sensitivity while maintaining a noise floor comparable to the passive version. Active electronics fully isolate the ribbon from the phantom supply, eliminating the risk of ribbon damage from 48 V applied through a TRS cable or a failed phantom rail.
Two Voices and Road-Ready Format
Like the passive R92, the R84A's motor produces deliberately different tonalities between the front and rear lobes of its figure-8 pattern — the front face runs brighter with more midrange presence, while the rear face is smoother and more forgiving of sibilance and transient aggression. The compact body (295 mm, 1.36 kg) and universal preamp compatibility make the R84A a standard touring ribbon — the same tonal character regardless of the quality of the preamp at the venue. In orchestral and scoring applications, the higher output and stable impedance remove the need for the high-gain, high-impedance ribbon-specific preamp that was a prerequisite for the passive R84.
KEY FEATURES
- Active version of the R84 — identical Big Ribbon 1.8-micron element (59.7 mm × 4.7 mm), 16.5 Hz tuning
- Active JFET electronics + Lehle transformer (Germany) — same topology as A440 and TRP/RPQ preamps
- +12 dB output over passive R84
- Output impedance: 92 Ω broadband (load-independent)
- Sensitivity: 6.3 mV/Pa (–44 dBV) into unloaded circuit
- Max SPL: 141+ dB (1% THD harmonic distortion >1 kHz)
- Power: P48 phantom, 7 mA
- Ribbon fully isolated from phantom supply — safe with any preamp
- Polar pattern: figure-8 (bidirectional)
- Dual tonality: front (brighter, more presence) / rear (smoother, reduced sibilance)
- 18-karat gold-plated grille basket — distinguishes R84A from passive R84
- Side-address pill-shaped body — mobile use and tight placement angles
- Off-axis rejection: up to 90 dB at 90°/270°
- 3 m captive cable, XLR-3M; softcase and manual included
- Dimensions: 295 mm (H) × 99 mm (W) × 64 mm (D); weight: 1.36 kg with cable
- Handmade in Pasadena, California, USA
TECHNICAL SPECIFICATIONS
- Operating principle: pressure gradient transducer (active, JFET)
- Polar pattern: figure-8 (bidirectional)
- Frequency range: <20 Hz – >20 kHz
- Max SPL: 141+ dB (1% THD >1 kHz)
- Sensitivity: 6.3 mV/Pa (–44 dBV) into unloaded circuit
- Output impedance: 92 Ω broadband
- Recommended load impedance: ≥1 kΩ
- Power: P48 phantom, 7 mA
- Polarity: Pin 2 + for positive pressure at front
- Off-axis rejection: up to 90 dB at 90°/270° (horizontal)
- Ribbon thickness: 1.8 µm; width: 4.7 mm; length: 59.7 mm
- Resonant tuning: 16.5 Hz
- Connector: XLR-3M on 3 m captive cable
- Dimensions: 295 mm (H) × 99 mm (W) × 64 mm (D)
- Weight: 1.36 kg (with cable)
- Made in: USA (Pasadena, CA)


