AEA RPQ503 500 Series Microphone Preamp and EQ - High-Gain Studio Precision
The AEA RPQ503 is a single-channel 500 Series microphone preamp and equalizer, built on the 3rd-generation circuit design of the acclaimed AEA RPQ3. With an ultra-high 68 kΩ input impedance, 85 dB of clean gain, and low-noise JFET op-amps, it delivers transparent, dynamic sound for ribbon, dynamic, and condenser microphones. The expanded CurveShaper™ EQ section offers sweepable low and high-frequency boost/cut controls, ideal for taming proximity effects or adding air to vocals and instruments. Handcrafted in the USA, the RPQ503 is a versatile, high-performance tool for professional recording and mixing.
Ultra-Clean Preamplification
The RPQ503’s 3rd-generation JFET circuitry provides up to 85 dB of clean gain with an ultra-low noise floor (EIN: -130 dBu, 40 Ω source). Its 68 kΩ input impedance (phantom power off) ensures ribbon and dynamic mics perform without tonal compromise, preserving rich lows, open highs, and fast transients. With +48V phantom power and an 11.3 kΩ impedance when engaged, it also supports condenser mics, making it a flexible front-end solution for any studio setup.
Expanded CurveShaper™ EQ
The RPQ503 features an enhanced EQ section with dual-concentric potentiometers for low and high-frequency bands, each offering ±20 dB boost/cut. The low-frequency shelf sweeps from 40 Hz to 675 Hz to control proximity effect or rumble, while the high-frequency bell (2.5 kHz to 30 kHz) adds presence or air without harshness. Both bands are bypassable via a single EQ IN switch, with center-detented gain knobs for precise settings, ensuring natural sound even at aggressive boosts.
Versatile and User-Friendly Design
With mic/line input switching (line mode bypasses the preamp stage), polarity inversion, and a continuously variable output trim (0 to +20 dB), the RPQ503 adapts to recording or mixdown tasks. Its low 50 Ω output impedance and +27 dBu max output level ensure compatibility with any audio interface or console. The 3-stage LED metering (-6 dBu green, +23 dBu red, variable yellow) provides clear signal monitoring, while the compact, USA-made design fits seamlessly into any 500 Series rack.
Key Features of the AEA RPQ503
- 1-channel 500 Series preamp with 3rd-gen AEA circuitry
- Ultra-high 68 kΩ input impedance (11.3 kΩ with +48V phantom)
- 7 to 85 dB clean gain for ribbon, dynamic, and condenser mics
- Expanded CurveShaper™ EQ: ±20 dB boost/cut, low (40–675 Hz), high (2.5–30 kHz)
- EQ in/out switch with center-detented gain controls
- Mic/line input switching, polarity switch, +48V phantom power
- Low noise: EIN -130 dBu (40 Ω source), THD+N 0.0018% at 30 dB gain
- 3-stage LED metering: -6 dBu (green), +23 dBu (red), variable yellow
- Max output: +27 dBu into 600 Ω load, 50 Ω output impedance
- Handcrafted in the USA, 3-year warranty
Technical Specifications
- Type: 500 Series microphone preamp and EQ
- Input Impedance: 68 kΩ (phantom off), 11.3 kΩ (phantom on)
- Gain: 7 to 65 dB (12-position switch), +20 dB output trim
- EIN: -130 dBu (40 Ω source), -128 dBu (150 Ω source), unweighted
- Frequency Response: 30 dB gain: -0.6 dB at 10 Hz, -3 dB at 160 kHz; 85 dB gain: -3 dB at 10 Hz and 160 kHz
- THD+N: 0.0018% (1 kHz, 22 Hz–22 kHz, +4 dBu output at 30 dB gain)
- Max Output Level: +27 dBu into 600 Ω load
- Output Impedance: 50 Ω
- Max Input Level: +20 dBu (minimum gain)
- EQ: Low shelf (40–675 Hz), high bell (2.5–30 kHz), ±20 dB boost/cut, bypassable
- Controls: Mic/line switch, +48V phantom, polarity switch, EQ in/out, dual-concentric EQ pots
- Metering: 3-stage LED (-6 dBu green, +23 dBu red, variable yellow)
- Dimensions: 1-space 500 Series module
- Warranty: 3-year limited
