AEA TRP3 is a two-channel, third-generation microphone preamplifier in a half-rack chassis, designed for passive ribbon microphones. The Gen 3 circuit by Fred Forssell delivers 68 kΩ input impedance (phantom off) and a gain range of 7–85 dB with THD+N of 0.0015% at 30 dB gain — among the lowest distortion figures in this class of preamps. The TRP3 shares topology and sonic character with the RPQ3 but omits the EQ section in favor of a more compact, road-ready format.
68 kΩ and 85 dB Gain — Purpose-Built for Passive Ribbons
Passive ribbon microphones demand high input impedance and high clean gain simultaneously — two requirements that most standard preamps address poorly. The TRP3 presents 68 kΩ (phantom off), allowing passive ribbons to operate without the high-frequency loading loss that occurs with standard 1.5–2.5 kΩ preamp inputs. With phantom engaged, input impedance drops to 11.3 kΩ due to the feed resistors required for 48 V delivery; still several times higher than typical mic preamps and sufficient for condenser and dynamic sources. Bandwidth at full 85 dB gain reaches –3 dB at 9 Hz and above 200 kHz — the full transient and low-frequency content of any microphone passes through without restriction. Maximum output of +27 dBu into 600 Ω provides headroom for long cable runs to consoles or converters.
HPF, Phantom and Portable Half-Rack Format
The switchable high-pass filter offers –3 dB at either 115 Hz or 230 Hz at 6 dB/octave — effective for controlling proximity effect and mechanical rumble without touching an EQ insert later in the chain. The twelve-position gain switch (+7 to +65 dB) combined with a continuous output trim (0 to +20 dB) gives a total range of 7–85 dB with repeatable, session-to-session settings. Per-channel +48 V phantom power and polarity reverse are individually switchable. The lightweight aluminum half-rack body is designed for location recording and studio use alike: a single TRP3 mounts in 1U with optional rack ears; two units fit side by side in 1U with the optional rack shelf, keeping a matched stereo pair in a single rack space.
KEY FEATURES
- 2-channel AEA Gen 3 mic preamp, half-rack format
- Input impedance: 68 kΩ (phantom off) / 11.3 kΩ (phantom on)
- Gain range: 7–85 dB (12-position switch +7 to +65 dB + output trim 0–+20 dB)
- THD+N: 0.0015% (1 kHz, 22 Hz–22 kHz, 30 dB gain, +4 dBu output)
- Bandwidth (85 dB gain): –3 dB at 9 Hz and >200 kHz
- Max output level: +27 dBu (600 Ω load)
- Output impedance: 50 Ω
- Max input level: +20 dBu (minimum gain)
- HPF: –3 dB at 115 Hz or 230 Hz (switchable, 6 dB/oct)
- +48 V phantom power per channel (switchable)
- Polarity reverse per channel
- External switching PSU (included)
- Optional accessories: rack ears (1 unit in 1U) and rack shelf (2 units in 1U)
- Handmade in Pasadena, California, USA
TECHNICAL SPECIFICATIONS
- Channels: 2
- Format: half-rack, 1U (with optional rack ears)
- Input impedance: 68 kΩ (phantom off) / 11.3 kΩ (phantom on)
- Output impedance: 50 Ω
- Gain range: 7 dB – 85 dB
- THD+N: 0.0015% (1 kHz, 30 dB gain, +4 dBu output)
- Bandwidth (85 dB gain): –3 dB at 9 Hz / >200 kHz
- Max input level: +20 dBu (minimum gain)
- Max output level: +27 dBu (600 Ω)
- HPF: –3 dB @ 115 Hz or 230 Hz, 6 dB/oct
- Phantom power: +48 V (per channel, switchable)
- Polarity reverse: yes (per channel)
- Power: external switching PSU
- Made in: USA (Pasadena, CA)
