Recording - August 2012 - 20

B Y PA U L V N U K J R .

Wes Dooley’s Audio Engineering Associates (AEA) is known for its line of high-end ribbon microphones as well as being one of the world’s foremost restoration specialists of vintage RCA ribbon models. AEA also manufactures a line of highend microphone preamps that, as you can guess, are designed to literally get the most out of your ribbon microphones. Today we are looking at AEA’s newest mic pre model, the RPQ 500, which is a few evolutionary steps up from AEA’s TRP (short for The Ribbon Pre) released in 2006. Reviewer Scott Dorsey gave us the lowdown on the TRP in our March 2007 issue and commented on the clarity it brought out in a ribbon microphone. Two years after its release came the RPQ, and while its raison d’être was still primarily the world of ribbon microphones, there were other improvements as well that went beyond ribbons: optional phantom power, a sweepable high-band eq called the Curve Shaper, and a variable low-frequency filter.

In between the input and output is a Low Frequency Filter control that is fully sweepable from 18 Hz to 360 Hz and drops the selected frequency down –20 dB, shelving, with 6 dB/octave slope. Next is the Curve Shaper, a sort of highband shelving eq. One control adjusts the circuit’s gain from 0 dB up to +20 dB, while the other selects the frequency from 2.1 kHz up to 26 kHz. Both the Curve Shaper and the Low Freq Filter include bypass buttons so they can be taken in and out of the signal path. Additionally the RPQ 500 has a phase button, a phantom power button, and a 3-stage signal level/clip LED meter. About the 500 series’ use of phantom power: On the original RPQ, there were two sets of XLR inputs, one for use with ribbons and devoid of voltage, and a second standard input with phantom power for use with typical condenser microphones. On the 500-Series version there is of course only one XLR input and its

AEA RPQ 500
The newest member of the AEA family, the RPQ 500, is a single channel from the 2-channel RPQ, designed for use in an API 500-Series style enclosure (For this review, I used the Radial Workhorse enclosure, reviewed in our October 2011 issue). All of the RPQ’s features are included as well as a new variation or two. Style, build, and functions The RPQ 500 is a single-slot module that is fully enclosed in a zinc-plated steel chassis with a 0.125" black tinted anodized aluminum front plate. It uses the same full-sized silver knurled knobs as its 19" rack mount sibling—it looks quite imposing sitting next to many other 500 series devices with their tightly spaced miniature controls and pots. As with the RPQ, signal flow starts with a 12-stepped Grayhill pot that goes from +7 dB up to +56 dB of preamp gain. This is followed by a variable output gain control that goes from 0 up to +19 dB. The FET output circuit also adds +6 dB of gain, so at full throttle the RPQ 500 can give you +81 dB of clean gain—yes, 81 dB, you read that correctly.
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RECORDING August 2012

The 500-Series format gains a remarkable tool for truly clean mic gain
phantom power is switchable in and out, so the same care needs to be taken as when using any mic pre with a ribbon microphone. The last feature is also specific to the RPQ 500, and that is a Mic/Line switch that changes the input from mic level to a line-level signal. This takes the input stage and phantom power out of the path and allows you to use the eq section alone during mixdown, on any source. Sound and use The RPQ 500 falls squarely in the Millennia Media, John Hardy and Grace Designs camp and holds its own with them all. Of those three I found it sonically closest to the John Hardy. It is clean and clear and simply stays out of the way and imposes no tone of its own to the mic. Where it differs from the pack is more in function than sound, as its impedance load is specifically tailored to ribbon mics, and, again, it offers +81 dB of gain, more than the competition’s +65 to +70 dB of gain. It’s easy to get a great level when tracking loud sources like drums, guitar cabinets and brass sections with a ribbon microphone, but on delicate acoustic guitar, soft crooning vocals, violins and voiceover work, I often end up pushing my mic pres to their limits, thus boosting their noise floor to the point where it becomes a detriment to the intimate recording I was attempting in the first place. With the RPQ 500 I achieved the single quietest signal with the lowest noise floor I have ever experienced with a ribbon microphone. The preamp plays no favorites in that category, delivering that pristine sound for ribbons from a Royer R-121 to AEA’s own R84 with a few Chinese-made suspects in between. On condensers like my Neumann KM 84s and my Brauner Phantom and even most modern tube microphones, gain typically is not an issue and here is where the RPQ 500 treads similar ground to my Millennia Media HV-3D. However, my biggest surprise came when pairing the RPQ 500 with a moving-coil/dynamic Shure SM-7B. I love this microphone and what it does for vocals and voiceovers, but too often I have the same experience as when I use low-output ribbons—too much

Recording - August 2012

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