AEA RPQ500 Versatile Mic Preamp
Versatile mic preamp in the 500 series format
The Versatile Mic Pre in the 500 series format
The RPQ500 module, designed after the successful RPQ preamp, provides the same ultra-clean, high-gain signal path that has earned AEA preamps their great reputation, but in a 500 series package. JFET circuit topology provides all the dynamics, subwoofer bass, and fast transients that your microphones can record. The NoLoad input impedance above 10K Ohms means the RPQ won’t load down a mic and change its sound. Low Energy Storage circuit design instantly recovers from overloads for superior dynamic performance. The original RPQ with CurveShaper was designed to fully capture every nuance of ribbon microphones: vintage or modern, passive or phantom powered. Engineers have discovered that the RPQ500 also complements their moving coil, condenser mics. By virtue of its sonic qualities and versatility, the VPR Alliance approved AEA RPQ500 is the tool of choice for all microphones whenever a true and pristine signal path is desired.
Two Peas in a Pod: Musical Preamp, Sweet EQ
The CurveShaper’s high-frequency filter boost enables you to add a little extra “presence” or “air” to your source. The circuit functions similarly to a conventional parametric shelving boost, but with a significant difference: the slope varies as both the CurveShaper and HF Gain controls are adjusted. This unique bell curve was designed with the intention to compensate for the high-frequency roll-off that is inherent to most ribbon microphones. But beyond ribbon mics, the smooth HF filter is remarkably well suited for brightening up condenser mics used at a distance, restore presence in overly “dry” acoustical environments, or even as a clean and transparent air-band boost on the 2-bus.
The CurveShaper’s low-frequency control easily removes boxiness and boominess in a fast and unobtrusive way. Ribbon mics are capable of delivering strong subwoofer lows, and can have a significant bass proximity effect. Such strong low-frequency content can mask high-frequency intelligibility, so the tunable LF filter was engineered to tame low-frequency energy to appropriate levels. Its -20dB shelving curve is ideally suited to reduce excessive proximity effect, opening up new possibilities to use ribbon mics in close-up applications.
Your Sound At Your Fingertips
With mixing consoles disappearing from control rooms, dedicated preamps can take on the role of providing a high-quality front end giving you intuitive control to make critical decisions during tracking rather than “fixing it in the mix”. The RPQ500 is a workhorse tool for your API 500 compatible rack. The Line/Mic switch bypasses the microphone gain stage and allows the EQ to be used for tracking with other preamps or during mixdown. Add the output level control, and the RPQ500 becomes a high-quality processing tool that can be used for mixing and mastering when combined with summing racks and mixers such as the Purple Audio Moiyn or the Roll Music Folcrom.
– One channel with 81dB of sweet and quiet JFET gain for all mics
– High frequency CurveShaper EQ and low frequency proximity control
– Mic and line inputs for mixdown EQ versatility
– Switchable phantom power, polarity, line/mic, and EQ inserts
– NoLoad 10k Ohm high-impedance circuitry providing better overall transients, frequency response, and higher output sensitivity
Applications & Audio
Using the HF CurveShaper EQ
The RPQ500 features a unique CurveShaper circuit that enables you to add a little extra “presence” or “air” to compensate for high-frequency losses that are inherent to most ribbon microphones, the result of distant mic placement, or to restore presence in a “dry” acoustical environment.
The circuit functions similarly to a conventional parametric shelving boost but with a significant difference: the slope and bandwidth varies as both the Curve Frequency and Curve Gain controls are adjusted.
From a technical standpoint, it is evident the EQ shape of the CurveShaper is a bell. At its lowest setting, the peak frequency of the CurveShaper is 30 kHz while at its highest setting, the peak frequency is 120 kHz. In many instances, a bell with a peak at 120 kHz is not very practical since it is above the human frequency threshold of hearing. But the CurveShaper has a very wide bandwidth that allows the left side of the bell to essentially act as a high-frequency shelf.
The Curve Frequency knob, at its lowest setting, will yield a gentler slope and wider bandwidth. As the frequency is raised, the slope becomes steeper while the bandwidth narrows.
To activate the CurveShaper EQ section, depress the HF IN switch. Start by adjusting the continuously variable Curve Frequency control. The frequency markings on the Curve Frequency dial indicate the +3dB break-frequency when the Curve Gain is at max. Select the desired frequency with the Curve Frequency knob, and then dial in the amount of boost you desire with the Curve Gain knob. The two controls are interactive. Use your ears to determine what frequency and gain setting sounds best.