The AEA RPQ503 is the next evolution in AEA’s renowned line of high-impedance, high-gain preamplifiers, bringing the celebrated sound of the RPQ3 to the 500 Series format. Featuring ultra-low-noise, low-distortion op-amps, an ultra-high 68 kΩ input impedance, and up to 85 dB of clean gain, the RPQ503 delivers unmatched clarity and detail—perfect for ribbon, condenser, and dynamic microphones alike. More than just an exceptional preamp stage, the RPQ503 includes an expanded EQ section with sweepable low- and high-frequency bands, offering up to ±20 dB of boost or cut on intuitive, dual-concentric controls. Open and transparent yet responsive and dynamic, the RPQ503 is a versatile front-end solution for any signal path.
Enhance Every Microphone
The RPQ503 was designed to work great on passive ribbon microphones, however, when a preamp works well with a passive ribbon microphone, it will excel on every microphone. At once open, transparent, and musical, the RPQ503 is a versatile tool for the front end of any signal path.
A Gain Powerhouse
The RPQ503 is a powerhouse that provides unparalleled high gain with low-noise. With 85db of clean gain, the RPQ503 gives you enough juice to record soft sources without ever having to worry about noise. The RPQ503 is the tool of choice for all microphones whenever a true and pristine signal path is desired. Our 3rd generation circuitry is the cleanest and most musical design we’ve done yet.
AEA RPQ503 500 Series Preamp & EQ
- 1-space 500 Series preamp with AEA’s 3rd-generation preamp circuitry.
- Ultra-high 68 kΩ input impedance (phantom power off) for optimal ribbon mic performance.
- Gain range from 7 to 85 dB for detailed, noise-free amplification.
- Expanded EQ section with LF/HF sweepable frequencies.
- Up to ±20 dB boost/cut for both low and high bands.
- EQ in/out switching with center detents on gain pots for quick bypass of individual bands.
- +48V phantom power, polarity reverse, and mic/line input switching.
- Made in the USA by AEA Ribbon Mics Inc. (est. 1964).
- Max Gain: 85 dB
- EIN -130 dBu typical (40 Ω source, unweighted), -128 dBu typical (150 Ω source, unweighted)
- Frequency Response 30 dB gain: -0.6 dB @ 10 Hz, -3 dB @ 160 kHz, 85 dB gain: -3 dB @ 10 Hz and 160 kHz
- THD+N 0.0018% (1 kHz, 22 Hz–22 kHz, 30 dB gain, +4 dBu output)
- Max Output Level +27 dBu into 600 Ω load
- Input Impedance 68 kΩ (phantom off), 11.3 kΩ (phantom on)
- Output Impedance 50 Ω
- Max Input Level +20 dBu (minimum gain)
- Mic Gain Control 12-position switch, +7 dB to +65 dB
- Output Trim Continuously variable, 0 to +20 dB
- EQ Type First-order shelving, ±20 dB boost/cut
- LF Sweep 40 Hz–675 Hz
- HF Sweep 2 kHz–28 kHz
- LED Meters Green (-20 dBu), Yellow (0 dBu), Red (+20 dBu, clip at +27 dBu)
- Dimensions 1.5” W × 6.8” D × 5.2” H (3.8 × 17.27 × 13.34 cm)
- Weight 12 oz (0.338 kg)

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