Recording - April 2011 - 24

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

JDK Audio
R20 Microphone Pre Amp, R24 Equalizer, and R22 Compressor
A famous maker’s new line comes out of the starting gate with three exceptional offerings
sufficient gain. The manufacturer agrees that low-output ribbon mics may not be the ideal partners for this preamp, although I can attest to the fact that the unit is clean enough to be run almost wide open when using said mics to get a good level for mellow singers and voiceover work.

JDK Audio is a brand new product line designed, engineered and built by API (Automated Processes, Inc.). API started the JDK offshoot as an outlet for designs and ideas that don’t necessarily fit into the usual API paradigm. Currently the JDK line consists of the R20 Microphone Preamp, R24 Equalizer, and R22 Compressor rackmount processors under review today, and the V-14 Equalizer, a 500 Series module version of the R22. Each unit looks strikingly like new-oldstock army surplus communications gear, housed in olive-green metal enclosures with military-style nameplates and black pullout rack handles. (This look probably comes from the line’s quickly-discontinued original name: Arsenal.) Each unit shares similar black knobs, silver switches, and a front mounted power switch and corresponding red jewel LED. Additionally, both the mic pre and compressor use essentially the same housing and feature a pair of matching moving-coil VU meters. One of the JDK line’s biggest innovations is in its implementation of IC chips instead of transformers, and the compressor’s gain reduction circuit. While chipbased audio gear is nothing new, JDK makes use of specially designed, functionspecific chips, a technology invented by API and licensed for manufacture to THAT Corp. Each chip is designed to emulate the sound and function of transformers minus the heat, weight and, better still, the cost.

+48V phantom power, a –20 dB Pad (–10 dB instrument), phase, and a choice of mic/line input source. As mentioned the R20 offers a true moving-coil VU meter (a rare but welcome touch on a pre) as well as a red LED clip light for level watching. The front of the unit contains a pair of 1 /4" instrument inputs, while the rear of the unit houses a pair of balanced XLR ins and outs as well as a pair of additional balanced 1/4" TRS outs. The outputs are wired in parallel and could be used to mult a signal to different recording and or monitoring sources when needed. (By the way, the other two units have identical rear-panel output layouts.) The R20 is a completely new design by the API team with no roots or ties to the past. As you would expect from a transformerless pre, it is of the clean “straight wire with gain” variety. Sonically the R20 has a very smooth and natural sound with a slight mid-forward presence. I would place it below the crystal cleanness of a Millennia or Grace, but still a touch more transparent and natural than a Daking Mic Pre One or Focusrite ISA One. In use Bottom line: this is a “what you put in is what you get out”-style preamp, and mojo junkies will need to look elsewhere. But with this sound the R20 works well on most everything; it sounded especially nice on vocals, acoustic guitar, drums, percussion and room mic duties. When you use it with low-output mics like ribbons, especially if the sound source isn’t on the high-volume side, the fairly modest 55 dB of gain that the R20 is designed to produce requires turning the unit up to obtain

R24
The R24 is a 2-channel equalizer that does not care if it’s used in dual mono or on a stereo source. Unlike the mic preamp, the R24 does have a touch of vintage roots, as it is an updated recreation of the old ASPI 562 4-band parametric eq from the late 1970s and early ’80s. Back then the 562 was actually distributed by API, hence the connection. Each channel features two rows of variable (non-stepped) pots. The top frequency row gives you four choices: 20 Hz to 200 Hz, 100 Hz to 1000 Hz, 500 Hz to 5000 Hz, and 2000 Hz to 20 kHz. The bottom row of larger pots gives you the choice to boost or cut up to 12 dB. While each band is fully sweepable and overlapping, there is no Q control, nor any option to switch the width of the eq curves. You also cannot change the highest and lowest bands to a shelf or a cut. Instead, the R24 offers a peak/bell curve that starts pretty wide and gets narrower as the frequency gets higher, thus reducing the overlap in frequencies. There are also no Hi or Low pass filters on the unit, nor any input and output gain controls for balancing the overall eq’d signal. The only other control offered is a global bypass for each channel, not the individual bands. Compared to fully-fledged modern channel strips or multi-featured plug-ins, this eq may seem quite limited in scope. However, if you look at many console and/or program equalizers from back in the day, that’s just how they roll, and that’s why I was and am pretty excited by this eq.

R20
The R20 is a 2-channel mic preamp. Each channel features a continuously variable gain pot with up to 55 dB of microphone and 31 dB of instrument gain. A quartet of switches handles
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RECORDING APRIL 2011

Recording - April 2011

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